MINIFICPP-2473 Add .clang-format to project

[martinzink]

Please check it againts your current settings and we can discuss if there are any discrepancies.

To generate .clang-format from your current ide settings:

• CLion: Settings/Editor/Code Style/C++/Scheme export
• (if you have a different ide and know how to export please share)

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[lordgamez]

Should we maybe add a CI check for the formatting for changed files?

[szaszm]

I don't think we need a CI check for formatting, exceptions are OK in my opinion, and this is just a tool for us to make IDE setup easier.

But if more people push for CI checks, we can still add it later. I wouldn't block this one.