clang-format: Use MacroBlock for Py_*_ALLOW_THREADS formatting

[Avasam]

Do not squash merge, to preserve the commit hash in .git-blame-ignore-revs

The first commit is applied formatting using the second commit's configs, and is 100% automated by just running clang-format.

Alternatively there's also Macros https://clang.llvm.org/docs/ClangFormatStyleOptions.html#macros which gets clang-format to try and expand specific macros, but that makes the formatter non-portable (I ran this PR on my Linux machine, and Macros makes clang-format crash because I don't have llvm-symbolizer on my PATH)

---

I prefer doing this over adding ; everywhere because then clang-format will also correctly increase indentation inside the macro block. Adding visual clarity that it is, indeed, a block.

Py_*_ALLOW_THREADS is standard to Python, so I don't feel like this is "special-casing" the formatter configs to pywin32.

PY_INTERFACE_PRECALL/PY_INTERFACE_POSTCALL, GUI_BGN_SAVE/GUI_END_SAVE and PyW32_BEGIN_ALLOW_THREADS/PyW32_END_ALLOW_THREADS (which are all the same thing), differ in that they're not block-scoped.

[mhammond]

If we are touching (almost) every Py_*_ALLOW_THREADS use, wouldn't it be better to add a trailing ; and not indent the code in between?