[Feature Request] Move entities with arrow keys

[Gamer-XP]

Sometimes I want to position entities more precisely, and changing positions manually is a bit inconvenient (even though you can use right-left to adjust value).

So, suggestion is: When entity is selected, allow to use arrow keys to move it around. I suggest moving it by half-grid size since it's the most common offset so far (at least, for me). Shift+Arrows may move it by 1 pixel. Or opposite: shift to use by half cell.