Remove isFinalized semantic tokens logic

[allisonchou]

Summary of the changes

• This is unfortunate, but after talking with Cyrus, it turns out Roslyn doesn't have an accurate way to tell if frozen partial semantics have been finalized. Occasionally, this issue results in C# continually returning false for the isFinalized property, which in turn means we never cache tokens.

• Currently, the only options here are to (1) remove frozen partial semantics or (2) don't use caching. This PR opts for (1), since frozen partial semantics are most valuable at document open, while caching should be valuable throughout the use the document. (1) also means that we don't have to ask the C# server for tokens every time the LSP server sends us a request.

• I tested and besides for the initial colorization potentially seeming a bit more delayed, there don't seem to be other noticeable drawbacks.

• There will also be a Roslyn side PR that will have to be dual inserted with this one: [to-do: add link]

• Fixes:
  [LSP] Semantic tokens isFinalized property continually returning false on document open roslyn#59777

[ryanbrandenburg]

Seems good from our end. I'm curious about the Removal of the Frozen Semantic stuff, is that something that's just going to be turned off for the LSP or is it getting removed entirely?

[allisonchou]

Seems good from our end. I'm curious about the Removal of the Frozen Semantic stuff, is that something that's just going to be turned off for the LSP or is it getting removed entirely?

Just turned off for Razor LSP since the isFinalized property only affects Razor in the first place

[allisonchou]

Superseded by dotnet/roslyn#60484