Arcade stool is now a block.

to use it it works the following:
- place the stool down next to an arcade machine
- sit on it
- right click (use) on the arcade, to set you as the active player

other things done:
- refactoring
- "light bar" above the arcade screen indicates if you are set as the
active player or not
- excluded right click from input disablement in TickHandler

Still buggy:
- while sitting on the stool entity, the player sometimes shifts upwards
for a few seconds and then pops back into the desired position