Add possibility to archive teams

[fm3]

Deleting teams can cause problems when they are still referenced. This is why #5108 forbids that.
It would, however, be a better user experience if such teams could (at least) be archived (without breaking things).

From the discussion in #5077:

Only “archive” the team (meaning it is not listed, and removed from users and datasets, but annotations, tasktypes and projects can still have it
→ todo: open tasks become inaccessible but are still listed for their owners (annotation access query needs to be adapted OR cancel them in the archiving call)
→ problem: user may be confused when editing task type / project that still have an archived team. May need warning message when viewing task type / project