Ability to customize grid for entity placement

[elluminance]

When pressing "G", you can toggle if entities will be locked to an 8x8 grid when moving them around. I commonly find myself needing to place things in a 4x4 grid instead - and it's frustrating to deal with manually moving entities to be on my "grid". This is especially frustrating considering simply clicking on an entity that's "unaligned" while grid-aligned mode is active will cause it to 'fix' its position, requiring me to move it again by typing in the correct coordinates.

It would be nice if I could adjust how the grid behavior works. as well as potentially having some kind of indicator if the grid is on. One idea for that I've seen before is showing gridlines and then the size of it can be adjusted by pressing G repeatedly would adjust the size of the grid from smallest to largest or vice-versa.

[Vegita2]

@elluminance Can you try out the pull request and add some feedback?

[elluminance]

I just tried it out - it seems really good from the little bit I've used it! It's even better than anything I could have hoped for, honestly.