CUNY Academic Commons

Breaking this off of #12821 where I mentioned our Sept group meeting discussion about the need for bulk deletion of Library items, especially with group cloning coming in #13198 -- choosing a simpler cloning approach there, and bringing over all admin-created Library items, may necessitate some post-clone cleanup of items pulled over but not relevant to the new group. Enter bulk deletion, where the cloned group's admin can prune away.

It would also be useful to be able to change the folders of items in bulk, though I believe there are difficulties here because an item can only be in one folder at a time, so there may be some work to enable changing multiple items in multiple folders to all be in the same folder.