add "messy" station trait; add party trash to hangover trait

[warriorstar-orion]

What Does This PR Do

This PR adds a new station trait, "messy", which generates several distinct kinds of messes (consisting of decals and relevant objects) on roundstart. It also adds a special "party" mess which spawns when the hangover trait is rolled.

Why It's Good For The Game

Seems in the spirit of station traits, gives janitors something to do early round instead of waiting for messes to occur.

Images of changes

For the station trait itself, there are the following mess kinds:

Bloody

Bloody messes choose a species color, as well as drop various body parts.

Robotic

Robotic messes use the "machine blood" color, and drop robot gibs.

Engineering

Engineering messes burn and break tiles, and drop glass shreds, tiny pieces of cable, rods, and tiles. Note it does not actually disconnect any cables, just drops small pieces of cable.

This is more for engineers to fix up than janitors.

Dirty

Dirty messes add dirt, insect guts, and other miscellaneous decals.

Cooking

Cooking messes cause flour, cooking oil, ants, and egg white decals, and drop plates, meat, and snackbowls.

Party

When the hangover trait is rolled, party messes are generated, which add confetti, vomit, cigarette butts, and broken bottles.

Testing

Repeated spawning in and checking placement and layout of generated messes.

Changelog

:cl: add: New station trait: messy station. The last shift didn't clean up after themselves! add: Hangover station trait now includes appropriately festive trash. /:cl: