Support excluding code analysis for specific file patterns like C_Cpp.codeAnalysis.exclude

[Aneureka]

As titled, think it would be helpful to have settings like C_Cpp.files.exclude or C_Cpp.codeAnalysis.exclude to avoid analyzing specific source files (e.g., large header files with ~100k lines of code, currently clangd analyzes these huge files and probably causes OOM) to prevent from occupying plenty of resources.

[HighCommander4]

See #185 for a similar request.