Implement group hover and selection

[Alecaddd]

Summary / How this PR fixes the problem?

Implement hover effect for groups, and the ability to select groups or child nodes by holding CTRL

ToDo

• [x] Ignore artboards and allow selecting/hover child items
• [ ] If an item is already select, don't go through the whole recursive parent detection again

[Alecaddd]

This needs some refinement as it's not possible to select items inside artboards. I will fix the recursive parent detection to account for those.

[Alecaddd]

@mbfraga the Utils.Array.insert_array_at_iarray() method fails the assertion if the selected items to add to a group are not one after another, aka different indexes. Any clue?

[Alecaddd]

Ready for a full review!

[Alecaddd]

Doing a yolo merge!