[EventPipe] Minor bug fixes, and remove redundant/unused code. (dotnet/coreclr#23956)

[EventPipe] Minor bug fixes, and remove redundant/unused code. (dotnet/coreclr#23956)

- Update MicrosoftDiagnosticsTracingTraceEventPackageVersion
- Delete connection if the request is unknown/unhandled
- Adding missing error handling.
  - Provider names must be defined.
- Some renaming, error handling, and build warnings.
- Removing test code, and merge EventPipe::Enable functions.
- Remove commented/non-used lines.

Commit migrated from https://github.com/dotnet/coreclr/commit/b388f6cd87d87f4a07fe966aaa1bc92f245165d9