[clang] [clang-format] Change BinPackParameters to an enum to add a BreakAlways (PR #101882)

[Owen Pan via cfe-commits]

owenca wrote:

There's a compiler warning:
```
In file included from /Users/Owen/llvm-project/clang/lib/Format/AffectedRangeManager.cpp:16:
/Users/Owen/llvm-project/clang/lib/Format/FormatToken.h:1982:13: warning: unused function 'startsNextParameter' [-Wunused-function]
 1982 | static bool startsNextParameter(const FormatToken &Current,
      |             ^~~~~~~~~~~~~~~~~~~
1 warning generated.
```

https://github.com/llvm/llvm-project/pull/101882