B2 - Zoom and Pan Capability in PixelCanvas #8

What?

Let the user be able to zoom in and out and pan side to side on the grid. We should not need to actually change constants like CELLSIZE, but there should be a way to scale the PixelCanvas in the program with JavaFX functionality, and also apply offsets to the rendering for panning.

DOD

• The user can zoom in and out
• User can move the grid around (visually pan the view port)