Code formatting with clang-format

[dwRchyngqxs]

I noticed that code style is inconsistent and some questionable practices are in place (aligning fields with tabs is a no no as not every text editor uses the same tab length).
Fixing it all manually is a time consuming and needlessly tedious task. I propose the use of a code formatter to keep the style consistent.
I chose the clang-format style "Microsoft" as it seems the closest to what is in the code-base.
Maybe clang-format is not the best tool. According to the Qt doc it is one of the tools proposed by the Qt editor so I though it would be a good candidate.

Tell me what you think of this.

[gyunaev]

You can add .clang-format but generally I don't like the huge changes which just do the formatting.

[dwRchyngqxs]

Yeah, it's almost impossible to make sure nothing was sneaked in these huge commits. Could either be done by a trusted maintainer or a bot (I don't think you're using bots though).
Then adding a CONTRIBUTING.md with code guidelines and/or a pre-merge github action that applies the formatting will help to stay style consistent.