Prevent accidental deletions via soft delete for groups

Overview

We should follow up on #32935 (closed) by expanding soft delete to include groups.

Proposal

Require a soft deletion period for group removal.

• Attempting to remove a group marks it for deletion. It should no longer immediately remove the group.
• After X days have elapsed, the project or group is deleted.
  • We should use the same soft delete configuration introduced in #32935 (closed).
• Attempting to delete something:
  • The "remove group" container for group should reflect the soft deletion period.
  • A project pending deletion should be marked for deletion on the group overview page (banner, similar to the archived project notice) and group list (with a pending delete badge).
  • Attempting to delete a group with the API should also result in the soft deletion period as described above.
• Recovering a group pending deletion:
  • Include a "restore" button in group settings that unarchives the project and removes the soft deletion state.
  • Should be able to restore/remove the soft deletion state via API.
• Soft deletion and restore should trigger an audit event.