[Scenario] Update repository behavior to match move/copy/link

Previously (in nasa/MCT-Plugins#136) new containment rules were introduced for repositories (My Tags, Mission Tags, etc) which involved introducing a Move operation when a "link" operation would normally occur.

Changes in support of nasa/mct#179 change the desired implementation of this; that issue introduces Move, Copy, and Copy Linked options when dragging and dropping. Changes are introduced here to account for the presence of a "Move" option in the platform:

* Revise policy to account for the availability of new action types (previously, Move had been implicitly disallowed)
* Remove dialog which notifies the user that a Move has occurred; this is no longer atypical behavior, so the dialog is not necessary.
* Prevent the "Copy Linked" option from appearing. Previous implementation had previously followed up on drag-drop initiated Link actions to complete them as a move; now that the user has specifically distinguished between Moves and Links, this is misleading/confusing.