[clang] [clang-format] Add KwBreakBeforeCaseLabel (PR #227668)

[Anan Yablonko via cfe-commits]

ananski-the-3rd wrote:

update:
I removed the additional pass. Waiting to hear:
- whether you accept my argument as to the necessity of the option.
- thoughts on naming.

Also, I could not find any use for CanBreakBefore. You suggested it as a replacement to the pass, which was removed anyways, so I assume it's no longer a requirement.

https://github.com/llvm/llvm-project/pull/227668