About The Pull Request

I'm removing bits of code that were defining the same variable inside a type multiple times.
It's like this PR: #46978

Why It's Good For The Game

Cleans code and re-adds some things that were accidentally removed. I'll provide details:

• The box of beanbags (/obj/item/storage/box/beanbag) lost its icon at some point. It seems like this was a mistake, so I've re-added that and remove the duplicate vars.
  
• The Shambler's Vendor had a typo leading to its light_color not being set. Now it's set (you'll have to squint):
  
• The cargo export for micro batteries was overriding the export for nano batteries. I fixed this, but there's another bug involving them (cargo exports no longer include subtypes when they shouldn't #50628) that makes testing this change awkward (I did test it though.)
• I also fixed the bag that cops in Families were spawning with being broken duped vars. @Iamgoofball says this change is the intended behaviour.

The rest is obvious enough.

Changelog

🆑
tweak: Beat cop in families now spawn with a cop dufflebag
fix: box of beanbags now has its correct icon instead of a generic box
fix: Shambler's Vendor now has correctly coloured ominous glow
fix: serving trays are no longer hidden from the autolathe
code: removed some instances of duplicate variables being defined in types
/:cl: