Introduce consistent line-length code formatter in pre-commit hook

[ezdac]

The gofmt (and gofumpt) code formatter do not want to enforce a particular line length.
However, I think we should introduce this for our project as a pre-commit hook.
There is golines, which defaults to a maximum of 100 columns per line, but is configurable.

Are there any other opinions about this?

[schmir]

#396 uses the golines-gofumpt hook with 120 characters line length limit

[jannikluhn]

golanci-lint enforces a line length limit, but we only run it in CI (via make lint-changes) not as a pre-commit hook.