VS Code Intellisense reports unknown data type after rename operation

## Issue Description ##
## Steps to Reproduce ##
1. Create an enum in its own .cs file. Name it `TheEnum`.
2. In a separate .cs file, declare a class and in it, declare a property of type `TheEnum`.
3. Save all files.
4. Go to the class, locate the property declaration and rename `TheEnum` to something else. Yes, rename from its usage, not its definition.
5. Renaming seems to work flawlessly, but now Intellisense says the new name you gave to the enum is not known.
## Expected Behavior ##

After the enum is renamed, Intellisense should recognize the new name.

## Actual Behavior ##

After renaming, Intellisense does not recognize the new name.

## Logs ##

### OmniSharp log ###
Post the output from Output-->OmniSharp log here

### C# log ###
Starting OmniSharp server at 12/13/2020, 2:46:55 AM
Target: c:\Users\webJo\source\repos\streiffmkt.api

OmniSharp server started.
Path: c:\Users\webJo\.vscode\extensions\ms-dotnettools.csharp-1.23.7\.omnisharp\1.37.4\OmniSharp.exe
PID: 23536

[info]: OmniSharp.Stdio.Host
Starting OmniSharp on Windows 6.2.9200.0 (x64)
[info]: OmniSharp.Services.DotNetCliService
DotNetPath set to dotnet
[info]: OmniSharp.MSBuild.Discovery.MSBuildLocator
Located 4 MSBuild instance(s)
1: Visual Studio Enterprise 2017 15.9.28307.586 - "C:\Program Files (x86)\Microsoft Visual Studio\2017\Enterprise\MSBuild\15.0\Bin"
2: Visual Studio Build Tools 2017 15.9.28307.1000 - "C:\Program Files (x86)\Microsoft Visual Studio\2017\BuildTools\MSBuild\15.0\Bin"
3: Visual Studio Community 2019 16.6.30225.117 - "C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Current\Bin"
4: StandAlone 16.8.0 - "c:\Users\webJo\.vscode\extensions\ms-dotnettools.csharp-1.23.7\.omnisharp\1.37.4\.msbuild\Current\Bin"
[info]: OmniSharp.MSBuild.Discovery.MSBuildLocator
Registered MSBuild instance: Visual Studio Community 2019 16.6.30225.117 - "C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Current\Bin"
[info]: OmniSharp.Cake.CakeProjectSystem
Detecting Cake files in 'c:\Users\webJo\source\repos\streiffmkt.api'.
[info]: OmniSharp.Cake.CakeProjectSystem
Could not find any Cake files
[info]: OmniSharp.MSBuild.ProjectSystem
No solution files found in 'c:\Users\webJo\source\repos\streiffmkt.api'
[info]: OmniSharp.MSBuild.ProjectManager
Queue project update for 'c:\Users\webJo\source\repos\streiffmkt.api\src\StreiffMkt.Api.csproj'
[info]: OmniSharp.MSBuild.ProjectManager
Queue project update for 'c:\Users\webJo\source\repos\streiffmkt.api\Tests\StreiffMkt.Api.Tests\StreiffMkt.Api.Tests.csproj'
[info]: OmniSharp.Script.ScriptProjectSystem
Detecting CSX files in 'c:\Users\webJo\source\repos\streiffmkt.api'.
[info]: OmniSharp.Script.ScriptProjectSystem
Could not find any CSX files
[info]: OmniSharp.WorkspaceInitializer
Invoking Workspace Options Provider: OmniSharp.Roslyn.CSharp.Services.CSharpFormattingWorkspaceOptionsProvider, Order: 0
[info]: OmniSharp.MSBuild.ProjectManager
Loading project: c:\Users\webJo\source\repos\streiffmkt.api\src\StreiffMkt.Api.csproj
[info]: OmniSharp.WorkspaceInitializer
Invoking Workspace Options Provider: OmniSharp.Roslyn.CSharp.Services.Completion.CompletionOptionsProvider, Order: 0
[info]: OmniSharp.WorkspaceInitializer
Invoking Workspace Options Provider: OmniSharp.Roslyn.CSharp.Services.RenameWorkspaceOptionsProvider, Order: 100
[info]: OmniSharp.WorkspaceInitializer
Invoking Workspace Options Provider: OmniSharp.Roslyn.CSharp.Services.ImplementTypeWorkspaceOptionsProvider, Order: 110
[info]: OmniSharp.WorkspaceInitializer
Invoking Workspace Options Provider: OmniSharp.Roslyn.CSharp.Services.BlockStructureWorkspaceOptionsProvider, Order: 140
[info]: OmniSharp.WorkspaceInitializer
Configuration finished.
[info]: OmniSharp.Stdio.Host
Omnisharp server running using Stdio at location 'c:\Users\webJo\source\repos\streiffmkt.api' on host 21980.
[info]: OmniSharp.MSBuild.ProjectManager
Successfully loaded project file 'c:\Users\webJo\source\repos\streiffmkt.api\src\StreiffMkt.Api.csproj'.
[info]: OmniSharp.MSBuild.ProjectManager
Adding project 'c:\Users\webJo\source\repos\streiffmkt.api\src\StreiffMkt.Api.csproj'
[info]: OmniSharp.MSBuild.ProjectManager
Loading project: c:\Users\webJo\source\repos\streiffmkt.api\Tests\StreiffMkt.Api.Tests\StreiffMkt.Api.Tests.csproj
[info]: OmniSharp.MSBuild.ProjectManager
Successfully loaded project file 'c:\Users\webJo\source\repos\streiffmkt.api\Tests\StreiffMkt.Api.Tests\StreiffMkt.Api.Tests.csproj'.
[info]: OmniSharp.MSBuild.ProjectManager
Adding project 'c:\Users\webJo\source\repos\streiffmkt.api\Tests\StreiffMkt.Api.Tests\StreiffMkt.Api.Tests.csproj'
[info]: OmniSharp.MSBuild.ProjectManager
Update project: StreiffMkt.Api
[info]: OmniSharp.MSBuild.ProjectManager
Update project: StreiffMkt.Api.Tests
[info]: OmniSharp.Roslyn.CSharp.Services.Refactoring.V2.RunCodeActionService
Applying code action: using System;
[info]: OmniSharp.Roslyn.CSharp.Services.Refactoring.V2.RunCodeActionService
Applying code action: using System.Collections.Generic;
[info]: OmniSharp.Roslyn.CSharp.Services.Refactoring.V2.RunCodeActionService
Applying code action: Wrap every parameter -> Align wrapped parameters
[info]: OmniSharp.Roslyn.CSharp.Services.Refactoring.V2.RunCodeActionService
Applying code action: Wrap every parameter -> Indent all parameters
[info]: OmniSharp.Roslyn.CSharp.Services.Refactoring.V2.RunCodeActionService
Applying code action: Unwrap parameter list -> Unwrap and indent all parameters
[info]: OmniSharp.Roslyn.CSharp.Services.Refactoring.V2.RunCodeActionService
Applying code action: Wrap long parameter list -> Align wrapped parameters
[info]: OmniSharp.Roslyn.CSharp.Services.Refactoring.V2.RunCodeActionService
Applying code action: Wrap long parameter list -> Indent all parameters
[info]: OmniSharp.Roslyn.CSharp.Services.Refactoring.V2.RunCodeActionService
Applying code action: Wrap long parameter list -> Indent all parameters
[info]: OmniSharp.Roslyn.CSharp.Services.Refactoring.V2.RunCodeActionService
Applying code action: Wrap long parameter list -> Indent wrapped parameters
[info]: OmniSharp.Roslyn.CSharp.Services.Refactoring.V2.RunCodeActionService
Applying code action: Wrap every parameter -> Indent all parameters
[info]: OmniSharp.Roslyn.CSharp.Services.Refactoring.V2.RunCodeActionService
Applying code action: Wrap long parameter list -> Indent wrapped parameters
[info]: OmniSharp.Roslyn.CSharp.Services.Refactoring.V2.RunCodeActionService
Applying code action: Wrap every parameter -> Indent all parameters
[info]: OmniSharp.Roslyn.CSharp.Services.Refactoring.V2.RunCodeActionService
Applying code action: Remove Unnecessary Usings
[info]: OmniSharp.Roslyn.CSharp.Services.Refactoring.V2.RunCodeActionService
Applying code action: Generate constructor 'MethodTracer(scopeName, logger, scopeNameProperty, traceLevel, extraProps)'
[info]: OmniSharp.Roslyn.CSharp.Services.Refactoring.V2.RunCodeActionService
Applying code action: Wrap every parameter -> Indent all parameters
[info]: OmniSharp.Roslyn.CSharp.Services.Refactoring.V2.RunCodeActionService
Applying code action: using System.Collections.Generic;
[info]: OmniSharp.Roslyn.CSharp.Services.Refactoring.V2.RunCodeActionService
Applying code action: using System.Collections.Generic;
[info]: OmniSharp.Roslyn.CSharp.Services.Refactoring.V2.RunCodeActionService
Applying code action: using StreiffMkt.Api.Logging;
[info]: OmniSharp.MSBuild.ProjectManager
Queue project update for 'c:\Users\webJo\source\repos\streiffmkt.api\src\StreiffMkt.Api.csproj'
[info]: OmniSharp.MSBuild.ProjectManager
Loading project: c:\Users\webJo\source\repos\streiffmkt.api\src\StreiffMkt.Api.csproj
[info]: OmniSharp.MSBuild.ProjectManager
Successfully loaded project file 'c:\Users\webJo\source\repos\streiffmkt.api\src\StreiffMkt.Api.csproj'.
[info]: OmniSharp.MSBuild.ProjectManager
Update project: StreiffMkt.Api
[info]: OmniSharp.MSBuild.ProjectManager
Queue project update for 'c:\Users\webJo\source\repos\streiffmkt.api\src\StreiffMkt.Api.csproj'
[info]: OmniSharp.MSBuild.ProjectManager
Loading project: c:\Users\webJo\source\repos\streiffmkt.api\src\StreiffMkt.Api.csproj
[info]: OmniSharp.MSBuild.ProjectManager
Successfully loaded project file 'c:\Users\webJo\source\repos\streiffmkt.api\src\StreiffMkt.Api.csproj'.
[info]: OmniSharp.MSBuild.ProjectManager
Update project: StreiffMkt.Api
[info]: OmniSharp.Roslyn.CSharp.Services.Refactoring.V2.RunCodeActionService
Applying code action: using StreiffMkt.Api.Logging;
[info]: OmniSharp.Roslyn.CSharp.Services.Refactoring.V2.RunCodeActionService
Applying code action: Remove Unnecessary Usings
[info]: OmniSharp.MSBuild.ProjectManager
Queue project update for 'c:\Users\webJo\source\repos\streiffmkt.api\Tests\StreiffMkt.Api.Tests\StreiffMkt.Api.Tests.csproj'
[info]: OmniSharp.MSBuild.ProjectManager
Loading project: c:\Users\webJo\source\repos\streiffmkt.api\Tests\StreiffMkt.Api.Tests\StreiffMkt.Api.Tests.csproj
[info]: OmniSharp.MSBuild.ProjectManager
Successfully loaded project file 'c:\Users\webJo\source\repos\streiffmkt.api\Tests\StreiffMkt.Api.Tests\StreiffMkt.Api.Tests.csproj'.
[info]: OmniSharp.MSBuild.ProjectManager
Update project: StreiffMkt.Api.Tests
[info]: OmniSharp.OmniSharpWorkspace
Miscellaneous file: c:\Users\webJo\source\repos\streiffmkt.api\src\obj\Debug\netcoreapp3.1\StreiffMkt.Api.MvcApplicationPartsAssemblyInfo.cs added to workspace
[info]: OmniSharp.Roslyn.CSharp.Services.Refactoring.V2.RunCodeActionService
Applying code action: Remove Unnecessary Usings
[info]: OmniSharp.Roslyn.CSharp.Services.Refactoring.V2.RunCodeActionService
Applying code action: Remove Unnecessary Usings

## Environment information ##

**VSCode version**: 1.51.1
**C# Extension**: 1.23.7

Dotnet Information
.NET Core SDK (reflecting any global.json):
Version: 3.1.301
Commit: 7feb845744

Runtime Environment:
OS Name: Windows
OS Version: 10.0.18363
OS Platform: Windows
RID: win10-x64
Base Path: C:\Program Files\dotnet\sdk\3.1.301\

Host (useful for support):
Version: 3.1.5
Commit: 65cd789777

.NET Core SDKs installed:
2.1.201 [C:\Program Files\dotnet\sdk]
2.1.202 [C:\Program Files\dotnet\sdk]
2.1.502 [C:\Program Files\dotnet\sdk]
2.1.503 [C:\Program Files\dotnet\sdk]
2.1.505 [C:\Program Files\dotnet\sdk]
3.1.301 [C:\Program Files\dotnet\sdk]

.NET Core runtimes installed:
Microsoft.AspNetCore.All 2.1.6 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
Microsoft.AspNetCore.All 2.1.7 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
Microsoft.AspNetCore.All 2.1.9 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
Microsoft.AspNetCore.All 2.1.19 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
Microsoft.AspNetCore.App 2.1.6 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 2.1.7 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 2.1.9 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 2.1.19 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 3.1.5 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.NETCore.App 2.0.7 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 2.0.9 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 2.1.6 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 2.1.7 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 2.1.9 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 2.1.19 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 3.1.5 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.WindowsDesktop.App 3.1.5 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]

To install additional .NET Core runtimes or SDKs:
https://aka.ms/dotnet-download

Visual Studio Code Extensions

|Extension|Author|Version|
|---|---|---|
|atlascode|atlassian|2.8.5|
|cpptools|ms-vscode|1.1.3|
|csharp|ms-dotnettools|1.23.7|
|debugger-for-chrome|msjsdiag|4.12.11|
|docomment|k--kato|0.1.19|
|git-easy|bibhasdn|1.11.0|
|git-graph|mhutchie|1.28.0|
|gitlens|eamodio|11.0.6|
|hexeditor|ms-vscode|1.3.0|
|remote-wsl|ms-vscode-remote|0.51.4|
|vscode-drawio|hediet|1.2.0|
|vscode-eslint|dbaeumer|2.1.13|
|vscode-language-pack-es|MS-CEINTL|1.51.2|
|vscode-markdownlint|DavidAnson|0.38.0|
|vscode-yaml|redhat|0.13.0|;