[clang] [clang-format] Add options to set number of empty lines after includes (PR #78957)

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

18 isn't correct  here as you can see here https://clang.llvm.org/docs/ClangFormatStyleOptions.html the "git" version is 19

https://github.com/llvm/llvm-project/pull/78957