Check for duplicated guids

[ivan-coder]

It would be nice if it could be checked for meta guids that are duplicated in different files, which can happen for instance in a scenario where you duplicate some file or folder inside Assets, but you do that duplicate outside Unity, and then commit and push. My artists must be somewhat special... but we've managed to get this duplicated guids in the repo and merged into main, all tests passing green. Do you guys think this enhancement could be done, or is it out of the scope of the action?