The 515 MegaPR early downport (#7783)

Co-authored-by: Selis <selis@xynolabs.com>
Co-authored-by: Selis <sirlionfur@hotmail.de>
Co-authored-by: Kashargul <144968721+Kashargul@users.noreply.github.com>
Co-authored-by: SatinIsle <thesatinisle@gmail.com>
Co-authored-by: Heroman <alesha3000@list.ru>
Co-authored-by: Casey <a.roaming.shadow@gmail.com>
Co-authored-by: Raeschen <rycoop29@gmail.com>

code/modules/shuttles/shuttle.dm

@@ -257,7 +257,7 @@
 
 	// Observer pattern pre-move
 	var/old_location = current_location
-	GLOB.shuttle_pre_move_event.raise_event(src, old_location, destination)
+	SEND_SIGNAL(src, COMSIG_OBSERVER_SHUTTLE_PRE_MOVE, old_location, destination)
 	current_location.shuttle_departed(src)
 
 	if(debug_logging)
@@ -273,7 +273,7 @@
 
 	// Observer pattern post-move
 	destination.shuttle_arrived(src)
-	GLOB.shuttle_moved_event.raise_event(src, old_location, destination)
+	SEND_SIGNAL(src, COMSIG_OBSERVER_SHUTTLE_MOVED, old_location, destination)
 
 	return TRUE