Remove older impls

[TheAngryByrd]

WHAT

🤖 Generated by Copilot at 0919866

Removed the NamedText type and related code from the project and replaced it with more efficient and consistent source text implementations. Simplified the LSP server implementation and the code fix scaffolding process. Updated the documentation and tests accordingly.

🤖 Generated by Copilot at 0919866

We're sailing on the Roslyn sea, with adaptive LSP We've left behind the NamedText, it was a heavy mess So heave away, me hearties, heave away with glee We'll test our code fixes with any IFSACSourceText

🚀🧹📝

WHY

We've been running on newer implementations for a while and seems to be time to clean up older implementations.

• Removed NamedText
• Removed FsAutocompleteLSP

Should I also remove any of the "seams" I put in like IFSACSourceText?

I also haven't refactored AdaptiveLSP just yet.

HOW

🤖 Generated by Copilot at 0919866

• Remove the NamedText type and its dependencies from the code base, replacing it with the RoslynSourceText type that implements the IFSACSourceText interface more efficiently and consistently (link, link, link, link, link)
• Simplify the LSP server implementation by removing the FsAutoComplete.Lsp.fs file and the FSharpLspServer type, and using the AdaptiveFSharpLspServer type instead (link, link, link, link, link, link, link, link, link)
• Update the scaffolding process and the documentation for creating a new code fix to reflect the removal of the FsAutoComplete.Lsp.fs file from the registration of the code fix (link, link, link, link, link, link, link)
• Modify the HelpersTests and the Tests modules in the test/FsAutoComplete.Tests.Lsp project to take a textFactory argument of type ISourceTextFactory to allow testing different implementations of the IFSACSourceText interface (link, link, link, link, link, link, link)
• Remove the unused initNamedText and addToNamedText functions from the Helpers module in the ./benchmarks/SourceTextBenchmarks.fs file, and the irrelevant Named_Text_changeText_everyUpdate benchmark from the SourceText_LineChanges_Benchmarks type in the same file (link, link, link)

[Krzysztof-Cieslak]

Should I also remove any of the "seams" I put in like IFSACSourceText?

yeah, I think so.

[Krzysztof-Cieslak]

I also haven't refactored AdaptiveLSP just yet.

That's fine; let's do it in separate PR, and focus this one on just removing things.