🔨 Switch Project to use useOvermind

[MichaelDeBoey]

Follow-up of #2782

[Saeris]

Sorry, looking through this I'm not seeing any value add here.

[MichaelDeBoey]

@Saeris These PRs are all my refactoring to useOvermind branches I already created.
I just didn't push them, 'cause the #Hacktoberfest issue came and I wanted to give everybody a chance to win their #Hacktoberfest t-shirt.
Now I already pushed some branches (and rebased them onto master), because I think there are still some small improvements here.

In this PR I changed the signature of sandboxPrivacyChanged to accept 0 | 1 | 2 instead of {privacy: 0 | 1 | 2}.
This because we want to change all Overmind actions/effects that only have 1 argument to accept only that type instead of an object (@christianalfoni said it somewhere, but can't find the comment anymore 😕)

So I think this one can be re-opened en merged? 🤔