[clang-tools-extra] [clang-tidy] Enhance modernize-use-starts-ends-with to handle substr patterns (PR #116033)

[Piotr Zegar via cfe-commits]

https://github.com/PiotrZSL approved this pull request.

Current version looks fine.
Take a look into comments, if something could be improved.

Ping once you finish (looking and/or fixing), so it could be merged.

https://github.com/llvm/llvm-project/pull/116033