Toolbelt & other quality of life improvements

This update adds a Toolbelt Upgrade that lets you change between different rows of the Toolbar! I am working on a similar upgrade for the Materials bar as well; that will be in an upcoming update. :)

I also added a bunch of quality-of-life things people have suggested:

• Middle-mouse-button functionality is improved: if the hovered pixel is a static buildable it will select the material that builds into it; it will also fallback from that to any specific drill target the material has. The middle mouse button also visually sends the swatch to the inventory slot.

• Brush-sizes for the Hand, Blender, and Laser (width) are now saved/restored in the player savedata for convenience

• 'M' hotkey has been added to jump to the Map tab

• Map generation has been made much more efficient (caches results more) to avoid regen delay when tabbing to it (also improved tab speed with the Inventory tab)

• BUGFIX: repaired a bug that was preventing food from properly restoring health

• BUGFIX: made hotkeys (including numbers) not trigger when in the Feedback Window text field

More updates coming soon! :)