[clang] [clang-format] Add new option: WrapNamespaceBodyWithNewlines (PR #106145)

[Owen Pan via cfe-commits]

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

Running `FormatTests` failed:
```
[ RUN      ] FormatTest.WrapNamespaceBodyWithEmptyLinesNever
Assertion failed: (TheLine->MatchingClosingBlockLineIndex > 0), function tryFitMultipleLinesInOne, file UnwrappedLineFormatter.cpp, line 390.
```

https://github.com/llvm/llvm-project/pull/106145