[clang-tools-extra] [clang-tidy] Add `readability-redundant-tag` check (PR #210007)

[purnima shrivastava via cfe-commits]

purnima-nlp wrote:

I have added new tests as suggested, ran clang-format and clang-tidy tests locally, My latest commit seems fine to me , please give feedback, Thankyou you taking me this far, i have learned a lot.
@zwuis @EugeneZelenko 

https://github.com/llvm/llvm-project/pull/210007