[clang] [clang-tools-extra] [clang-tidy][clang][diagnostics] Unify system header/macro supression (PR #193774)

[Donát Nagy via cfe-commits]

NagyDonat wrote:

@AaronBallman @tbaederr @dbartol Gentle ping – I would be grateful for a review of the  NFC changes within `DiagnosticIDs.{cpp,h}`.

If you don't have time to review this, then please suggest someone who may be able to help.

https://github.com/llvm/llvm-project/pull/193774