Provides four validation actions:
Store Annotations: save selected images to the SQLite database (persistent, shared with ClassiPyR)
Relabel Selected: move selected images to a different class (session-only, logged in rv$corrections)
Relabel Class: move ALL images of the current class in the current region to a different class (session-only)
Invalidate Class: mark an entire class as non-biological / unclassified (session-only)