Use taplo to check and format `toml`s

[leandro-lucarella-frequenz]

The same as we check and format python files automatically, it would be good to do the same with pyproject.toml (and any other toml file) to make sure we have a consistent formatting across projects and can detect errors early.

taplo is a nice tool written in rust that can do both (and even check a toml semantically against a json schema).