Rework Stencil Table

Stencils are now registered like everything else.
Blank-Patterns are also registered, so other items can also be used potentially. (Could be changed to an event for more flexibility)
Currently their ID of stencils is assigned automatically by their position in the list.
New Stencil-UI
Ability to put Stencil-buttons on the right side of the stencil UI (that's totally for something I've planned.)
Fix Tool-Station rendering actually drawing the slots twice as big as they should be?