An action that groups the current active selection. This action would live under the Selection actions context menu, and would be accompanied by the Ctrl+G hotkey. This would group the items together, and would treat the group of items as a single item - potentially so you can have a hierarchy of groups within groups, so that the user could manage "collections of images within a collection&
I feel like it is more intuitive to access the actions that can be done to a selection directly through the right-click menu rather than under actions that can be done to selected images.
See the following image for a visual representation:
https://imgur.com/ouLJK6E
