[clang-tools-extra] [clang-tidy] Add new check 'readability-inconsistent-ifelse-braces' (PR #162361)

[Davide Cunial via cfe-commits]

capitan-davide wrote:

> Overall looks good. Did you try running it on some codebases to find any FP/incorrect fixes? A good idea would be to run at least on LLVM (like `clang` or `clang-tools-extra`):
> 
> ```
> python3 clang-tools-extra/clang-tidy/tool/run-clang-tidy.py -checks='-*,readability-inconsistent-ifelse-braces' -clang-tidy-binary build/bin/clang-tidy -quiet -hide-progress -p build/ -fix clang-tools-extra/
> ```

`clang-tools-extra` generates a number of matches, overall they look correct.

[fixes.patch](https://github.com/user-attachments/files/24327662/fixes.patch)



https://github.com/llvm/llvm-project/pull/162361