use ternary search tree for uris instead of paths, fyi @bpasero, @sandy081, @roblourens, https://github.com/microsoft/vscode/issues/93368

Add warning about long generated IPC paths, fix #86382

add compareSubstring, compareSubstringIgnoreCase and adopt for search tree so that it will be fit for case-in-sensitive compare, https://github.com/microsoft/vscode/issues/93368

Use markdownDescription for snippet.body

Update recommendations for C#.

The C# extension moved to a new publisher ID and the recommendations
need updating.

Fixes #94557