Fixes wheelchairs [TESTMERGE ME :)] (#42894)

Changelog

cl
fix: Buckle objects can now properly specify lying angle
fix: Wheelchairs and other such vehicles let you use UIs even if your legs don't work
fix: You can now pull objects while in a wheelchair even if your legs don't work
fix: You no longer have a chance of sleeping upside down in a bed
tweak: No longer randomises lying direction a second time on fall
/cl

code: simplified can_stand code

fixes #41703

code/game/objects/structures/beds_chairs/bed.dm

@@ -14,7 +14,7 @@
 	icon = 'icons/obj/objects.dmi'
 	anchored = TRUE
 	can_buckle = TRUE
-	buckle_lying = TRUE
+	buckle_lying = 90
 	resistance_flags = FLAMMABLE
 	max_integrity = 100
 	integrity_failure = 30

code/game/objects/structures/tables_racks.dm

@@ -413,7 +413,7 @@
 	buildstack = /obj/item/stack/sheet/mineral/silver
 	smooth = SMOOTH_FALSE
 	can_buckle = 1
-	buckle_lying = 1
+	buckle_lying = -1
 	buckle_requires_restraints = 1
 	var/mob/living/carbon/human/patient = null
 	var/obj/machinery/computer/operating/computer = null