[clang] [clang-format] Add BreakBeforeTemplateClose option (PR #118046)

[Owen Pan via cfe-commits]

https://github.com/owenca commented:

About the test cases:
- Call `verifyFormat` instead of `verifyNoChange` whenever possible.
- Don't end a test case with a newline. (Search for `\n",` and `\n")`.)
- Capitalize the first word of a comment and end the comment with a `.` (or `:` if appropriate).

https://github.com/llvm/llvm-project/pull/118046