[clang-tools-extra] [clang-tidy]Add new check readability-avoid-nested-conditional-operator (PR #78022)

[Piotr Zegar via cfe-commits]

https://github.com/PiotrZSL requested changes to this pull request.

Just few nits, from functional point of view check is good even now.

https://github.com/llvm/llvm-project/pull/78022