Add crate shelves

[Casper3667]

Ports shiptest-ss13/Shiptest#2374
The warehous has been redesigned to incorporate new shelves that can each carry up to 3 crates. The warehouse now spawns with the crates already on the shelves and the related code has been updated to account for this and still spawn things inside of them.
The back room in the warehouse also lost its camera, to give a chance for antags and other shenanigans to occur back there.

[Casper3667]

!review

[Arrow768]

Some minor style issues, but other than that it looks good.

It could be nice to have a radial menu when removing a crate to easily select a specific crate.

[Casper3667]

Some minor style issues, but other than that it looks good.

It could be nice to have a radial menu when removing a crate to easily select a specific crate.

Would the current ability to click-drag specific crates not be even easier?

[Batrachophreno]

Hovering over the crates to get its name in the lower-left corner should be more than sufficient, IMO, to justify click-drag. Especially with screentips in the pipeline that will make the name of hovered objects even more explicit/visible. I could see a radial menu being preferable if the only way to tell crates apart was by their physical appearance, but if you can see the name, I think a radial menu just adds an extra unnecessary click, which would of course be a sin.

I'm going to add an approval to this on that basis, but I'll also remark that I'd still want to wait to confirmArrow is cool w/ just click-drag too, before any merge!