Activities mif removal 11002

This adds only a single commit to https://github.com/openmicroscopy/openmicroscopy/pull/1203 to remove all MIF-specific handling from the Activities panel, since this is now handled BEFORE we submit to chgrp or delete.

Tricky to test if you've also got https://github.com/openmicroscopy/openmicroscopy/pull/1221 merged in, since you won't be able to go ahead with chgrp or delete of a MIF. However, you can test delete or chgrp error handling by choosing to delete or chgrp (E.g. empty Dataset), but before you hit "OK", use Insight (or webclient in a different browser/window to delete the Dataset).
Should see standard error handling in Activities (which will be the same for MIFs now).