[clang] [clang-format] Separate License text and include blocks (PR #77918)

[Björn Schäpers via cfe-commits]

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

I think splitting the two features would be better.

Also please add a note to the changelog.

https://github.com/llvm/llvm-project/pull/77918