[clang] [clang][ssaf] Add ssaf-format to validate and convert summaries (PR #185575)

[Aviral Goel via cfe-commits]

aviralg wrote:

Will be renamed to `clang-ssaf-format` similar to https://github.com/llvm/llvm-project/pull/185631

https://github.com/llvm/llvm-project/pull/185575