Blender Git Loki

Outliner: Don't show id operations (make single user) when not supported

For the make single user operation to work we expect a parent of the
datablock to be around. However this is often not the case when not
accessing the data from Scenes or Viewlayer display modes.

For now we simply not show them in the other cases. They can be added
later though, by testing the outliner tree parent compatibility with the
expected parent id.

Fix T71673
Differential Revision: https://developer.blender.org/D6276