Multiple deletion of USS folders/files

[katelynienaber]

We should allow users to select multiple USS files & folders in the tree view, and delete them.

Acceptance criteria:

• Multiple USS files and/or folders can be selected in the tree for deletion (but not profiles, for consistency with DS tree)
• Selected items can be deleted by pressing the "delete" key (be careful, this hotkey is already associated with deletion of DS/members!! So that needs to be dealt with)
• Selected items can be deleted via the context menu
• A progress bar is shown during deletion (for consistency with DS & Jobs tree)

This issue is related to the following other multi-delete issues:

• Add progress bar for multi-delete in Jobs tree
• Multi-select actions for DS tree

[JillieBeanSim]

this has been completed