Fix more style errors and use uncrustify to check style in CI

It's a rainy day so time for cleanup. With things like !486 (merged) (and many more before that) finally in we can improve further on consistent indent and readability.

@devrtz discussed automatic checks a while ago and so I finally went ahead and added that. While writing a small shell script to do that I noticed that mutter has a nice python one that doesn't check the whole file but only the changed hunks by Carlos Garnacho so I grabed that.

This goes on top of !463 (merged) and the first commits fix the worst offenders. We still have lots of missing space before brace but let's let that slip by now as it would introduce lots of noise. We check it though se we can clean up parts we work on upfront.

As this is on top of !463 (merged) it's more fun to review once that landed and hence draft.