.NET test debugging extension path length restriction

## Issue Description ##
## Steps to Reproduce ##

1. Create a .NET Core test using xUnit
2. Attempt to debug .NET Core test using the Debug Test functionality above the unit test (picture for guide)
3. Observe error in .NET Test Log output stating the path to the extension exceeds the maximum allowed (103 characters)

## Expected Behavior ##

- .NET test debugger does not error and debugging commences

## Actual Behavior ##


## Logs ##

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

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

## Environment information ##

**VSCode version**: 1.50.1
**C# Extension**: 1.23.4

Mono Information
OmniSharp using global mono :6.12.0
Dotnet Information
.NET Core SDK (reflecting any global.json):
Version: 3.1.402
Commit: 9b5de826fd

Runtime Environment:
OS Name: Mac OS X
OS Version: 10.15
OS Platform: Darwin
RID: osx.10.15-x64
Base Path: /usr/local/share/dotnet/sdk/3.1.402/

Host (useful for support):
Version: 3.1.8
Commit: 9c1330dedd

.NET Core SDKs installed:
3.1.108 [/usr/local/share/dotnet/sdk]
3.1.402 [/usr/local/share/dotnet/sdk]

.NET Core runtimes installed:
Microsoft.AspNetCore.App 3.1.8 [/usr/local/share/dotnet/shared/Microsoft.AspNetCore.App]
Microsoft.NETCore.App 2.1.22 [/usr/local/share/dotnet/shared/Microsoft.NETCore.App]
Microsoft.NETCore.App 3.1.8 [/usr/local/share/dotnet/shared/Microsoft.NETCore.App]

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

Visual Studio Code Extensions

|Extension|Author|Version|
|---|---|---|
|azurerm-vscode-tools|msazurermtools|0.13.0|
|csharp|ms-dotnettools|1.23.4|
|markdown-table-formatter|fcrespo82|2.1.3|
|mssql|ms-mssql|1.9.0|
|plantuml|jebbs|2.13.14|
|powershell|ms-vscode|2020.6.0|
|remote-containers|ms-vscode-remote|0.145.1|
|vscode-docker|ms-azuretools|1.7.0|
|vscode-dotnet-runtime|ms-dotnettools|0.1.2|
|vscode-scss-formatter|sibiraj-s|2.0.2|
|vscode-test-explorer|hbenl|2.19.1|
|vsliveshare|ms-vsliveshare|1.0.3014|;