Added Quick bar, Base inventory, Fuel reservoir, drag and drop between bars.
Added base and fuel reservoir on map, also quick bar (seen all the time) and base inventory (seen only when inventory is open and when robot is near the base). Still missing crafting buttons (will be added soon; probably on the right side of Base inventory). Player is able to drag and drop items between bars.
Fuel reservoir (will be better seen in the game when the background is drawn):