MODSuit clothing icon files can be overridden by its skin

[kyunkyunkyun]

What Does This PR Do

Kinda finishes porting of https://github.com/tgstation/tgstation/pull/65733

It was ported only particularly by Qwerty and never actually worked We also have sprite_sheets, so i added support for them as well

Removes outdated proc refit_for_species - it messed up with icon_override and we don't use it at all

Why It's Good For The Game

Only good for downstreams. Otherwise no affect (maybe a bit less performance i believe cos of added procs?) We had to do some real shit to create modsuits on SS220, with these changes it will be much more easier

Testing

Tested on downstream. It worked, no runtimes. Also tested on upstream (there), spawned some modsuits - nothing has changed, everything is working as always

Here is an example of how skins looks like on downstream with the changes. It might be shortened by using defines, tho

Declaration

• [x] I confirm that I either do not require pre-approval for this PR, or I have obtained such approval and have included a screenshot to demonstrate this below.

Changelog

NPFC