As the owner of a Space, I should be able to review / undo previous Moderations

(User Story, Investigate , Priority: Medium, Test Status: No automated tests yet , Reported By Justin du Coeur, )
Conversations, Moderation
Summary: Suggested by dsrtao: "Handing over mod authority is sharing control: it's necessary for certain traffic levels, and scary. It's best if there's an undo available, preferably along with an easily reviewable history list."
This specifically applies to Spaces with multiple Moderators -- the Owner may want to be able to review what the Moderators are doing, especially for newer Moderators.