Welded Lockers Don't Leak Miasma

[GORE]

https://github.com/goonstation/goonstation/pull/1025

Simply putting them inside a locker (which has air-slits) or a disposal bin (which is usually open) should not block the airflow or miasma-spread. I am all with Flaborized on this one.

Some extra steps like welding the lockers slits shut via adding a plate to the locker with a welder-in-hand should be necessary to hide a locker inside a corpse.
Otherwise we have to check every locker again.

Checking every air-slit-welded locker should not be too bad in comparison to checking EVERY locker.