Collision detection when inserting and moving items

[christianbrugger]

Features to be implemented:

• [ ] Do not connect to invalid items
  • [ ] Connector (Logicitem)
  • [ ] Linetree
• [ ] Do not anticipate invalid items
  • [ ] Connector (is_connected)
  • [ ] Linetree (edge indicators)
• [x] Implement basic invalid painting for Linetrees
  • [x] increase shape / bounding box for Linetree to Logicitem fraction
• [x] Make invalid state depending on connectivity
  • [x] output to output -> invalid (Connector)
  • [x] two outputs driving Linetree -> invalid (Connector, Linetree)
• [x] Update surrounding based on invalid bounding rect
  • [x] InsertableItem move (single item)
  • [x] Selection move (multiple items)
• [ ] Update inserting line to not collide with invalid lines.