Extra control placement 3039

[Ethan-Guttman]

This closes the good first issue #3039 (Allow controls to be placed at top-center, bottom-center, left-center, and right-center)

example pictures showcasing all four new positions:

Multiple ctrls will have margins between themselves like the already existing positions. However, depending on their widths in the top and bottom center they can look weird (smaller elements floating left).

I ordered the positions code in the css and map.js files by going from top-left to center-left clockwise listing each position too.