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
• [x] CTRL + Click on an item inside a selected group should select the item
• [x] If an item is already selected, don't go through the whole recursive parent detection again
• [x] Groups inside an artboard are selectable via click on an empty area. They should not
• [x] Double clicking an item inside a group should "open" the group, and select the double clicked item

[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!