General maintenance for wall mounts (#93534)

## About The Pull Request
- Fixes #93392
- Replaces all custom callbacks with call to `deconstruct()`. The
callbacks weren't necessary as it did the same thing as `deconstruct()`
but in an round about way
- Removed duplicate `Initialize()` procs and the params `building` &
`ndir` from all wall mounts. Makes everything cleaner

## Changelog
🆑
fix: wall mounts placed by player now falls off when the wall they are
mounted on is destroyed
code: cleaned up wall mount code
/🆑

code/modules/security_levels/keycard_authentication.dm

@@ -164,7 +164,8 @@ MAPPING_DIRECTIONAL_HELPERS(/obj/machinery/keycard_auth/wall_mounted, 26)
 
 /obj/machinery/keycard_auth/wall_mounted/Initialize(mapload)
 	. = ..()
-	find_and_hang_on_wall()
+	if(mapload)
+		find_and_hang_on_wall()
 
 GLOBAL_VAR_INIT(emergency_access, FALSE)
 /proc/make_maint_all_access()