Poking at door animation timers

Created by: Sprok0

Replaces the sleep(10)s strewn throughout door opening/closing with sleep(animation_delay), allowing for doors to finish opening sooner or later as needed. Gives doors with different animation lengths delays based on the number of frames before the final icon. Windoors let you pass about a quarter second sooner, certain fancy airlocks a bit later. Pod doors no longer hang open for like a full second before allowing passage.

Fixes #12324 (closed) Removes a workaround for a byond bug that doesn't seem to exist anymore. Removes an effectively identical child proc from firedoors.