Slowdown on pulling (#21056)

* slowdown on pulling

* slowdown only when pulling structure or machinery

* moving speed modifier to /mob/living/carbon instead of all atoms

* added pull_speed to /atom/movable, moved movement_delay proc to carbon/human

* no-slowdown-trash-bin

* Update code/game/atoms_movable.dm

Co-authored-by: Ryan <80364400+Sirryan2002@users.noreply.github.com>

* removed pull_speed on /obj/item/storage/bag/trash, no need to set this

* more 0 pull_speed objects

* added gravity check, moved pull_speed to /obj

---------

Co-authored-by: Ryan <80364400+Sirryan2002@users.noreply.github.com>

code/game/objects/structures.dm

@@ -3,6 +3,7 @@
 	pressure_resistance = 8
 	max_integrity = 300
 	face_while_pulling = TRUE
+	pull_speed = 0.5
 	var/climbable
 	var/mob/living/climber
 	var/broken = FALSE