Scene collections is disconnected from scenes

[GeorgesStavracas]

Management of scene collections is disconnected from the scenes themselves, and handled in a menu (!).

It should probably be moved closer to scenes, and managed through a separate dialog.

TODO: references

[Warchamp7]

Streamlabs has tackled this idea much the same way I desire to

Things I dislike about their implementation:

• The dropdown menu is the only place you can change collections
  
  You cannot do so from the manage window

• Controls are only visible on hover in the management window
  

• Not possible to bulk delete, has to be done 1 at a time with a confirmation window for each
  

• The + button next to the collections dropdown is the Add scene button. Not an add collection button
  

[GeorgesStavracas]

Thanks. I think the mockups recently pushed cover pretty much the entire featureset of these references.

This issue is blocked on #6 being implemented.