C#: Add most medium precision queries to the code-quality-extended suite.

[michaelnebel]

In this PR we add most medium precision queries to the codeql-quality-extended suite, with the exception of

• cs/xmldoc/* queries as they produce an overwhelming number of results (they are also excluded for other languages).
• cs/captured-foreach-variable as this query is related to change in semantics between C# 4 and C# 5.

DCA looks good

• The queries don't appear to produce an overwhelming number of results.
• The performance when adding the queries looks acceptable (adding medium precision queries adds to 30% to the analysis time compared to only running queries with precision very-high and high).

[Copilot]

Pull Request Overview

This PR adds all medium precision quality queries to the C# code-quality-extended query suite by updating query metadata to include the "quality" tag while preserving existing tags.

• Updates 42 C# queries by adding the "quality" tag to their metadata
• Reorganizes existing tags to maintain proper formatting with "quality" as the primary tag
• Updates the expected query suite output to reflect the newly included queries

Reviewed Changes

Copilot reviewed 44 out of 44 changed files in this pull request and generated no comments.

File	Description
Various .ql files (42 total)	Added "quality" tag while preserving existing tags like "maintainability", "reliability", etc.
not_included_in_qls.expected	Removed queries that are now included in the quality suite
csharp-code-quality-extended.qls.expected	Added 42 new queries to the expected output

[hvitved]

I'm not convinced we should add this query; the semantics of capturing a foreach variable has been stable since C# 5, which was released in 2012.

[michaelnebel]

Makes sense! I was also considering it, since C# 5 is very old and it probably has limited value. Thank you for pointing it out!
Will open another PR for deprecating the query instead.

[michaelnebel]

@hvitved: Since your last review, the query cs/captured-foreach-variable and cs/xmldoc/* queries have been removed from the code-quality-extended suite. The latter was removed in its entirety to align with other languages.

[michaelnebel]

@hvitved: Added a change note since your last review.