[UI] Improve drag-and-drop support in APL editor

[hillerstorm]

Doing a ton of APL editing highlighted a few missing features that would really speed things up, so I added them!

• Drag and drop APL values inside an Any of / All of
  • Not restricted to the same list, can be moved in/out any number of levels and even between different APL actions
• Being able to copy an APL value inside an Any of / All of
• Clearer indication of what block will be deleted inside nested Any of / All of
• Having the whole block show up as the drag-placeholder instead of just the move-button

Any feedback is appreciated!

drag_n_drop.mp4

[1337LutZ]

Yes, this is what I meant :D

[1337LutZ]

I haven't tested the feature myself, but code wise it looks cleaner :D thanks for making some of the small util fns