`with` expressions don't seem to work in OOP

Tracks TODO in code: https://github.com/davidwengier/razor/blob/CohostGoToImplementation/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/RazorDocumentServiceBase.cs#L44

The TODO tracks a line of code that used to be this:
https://github.com/dotnet/razor/blob/main/src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/GoToDefinition/RemoteGoToDefinitionService.cs#L72

This fails with an exception about not being able to find `set_LanguageKind`.

Start with the TODO at src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/RazorDocumentServiceBase.cs#L44 and compare it with the former implementation in src/Razor/src/Microsoft.CodeAnalysis.Remote.Razor/GoToDefinition/RemoteGoToDefinitionService.cs#L72. Reproduce the failure and trace the exception about the missing set_LanguageKind. Done means the with-expression path no longer fails with that exception.

Written by the indexing model from the issue text.