Makes check_teleport_valid pure & signal clean up (#90738)

- Closes #90704

The following changes were implemented for this
- Moved sending signals `COMSIG_MOVABLE_TELEPORTING` &
`COMSIG_ATOM_INTERCEPT_TELEPORTING` from `check_teleport_valid` into
`do_teleport`. These 2 signals were causing all the side effects
- Removed signals `COMSIG_ATOM_INTERCEPT_TELEPORTED` &
`COMSIG_MOVABLE_TELEPORTED` as the above 2 signals can do their jobs &
block the teleport if needed so these signals became obsolete
- Removed define `COMPONENT_BLOCK_TELEPORT` in favour of returning a
positive value if teleport was successfully blocked. Having 2 signals
located in 2 separate files use this same define doesn't look great.

🆑
code: cleans up teleportation code. `check_teleport_valid` is now a pure
function with no side effects
/🆑

code/game/objects/items/implants/security/implant_noteleport.dm

@@ -28,7 +28,7 @@
 	UnregisterSignal(target, COMSIG_MOB_PRE_JAUNT)
 	return TRUE
 
-/// Signal for COMSIG_MOVABLE_TELEPORTED that blocks teleports and stuns the would-be-teleportee.
+/// Signal for COMSIG_MOVABLE_TELEPORTING that blocks teleports and stuns the would-be-teleportee.
 /obj/item/implant/teleport_blocker/proc/on_teleport(mob/living/teleportee, atom/destination, channel)
 	SIGNAL_HANDLER
 
@@ -38,7 +38,7 @@
 	var/datum/effect_system/spark_spread/quantum/spark_system = new()
 	spark_system.set_up(5, TRUE, teleportee)
 	spark_system.start()
-	return COMPONENT_BLOCK_TELEPORT
+	return TRUE
 
 /// Signal for COMSIG_MOB_PRE_JAUNT that prevents a user from entering a jaunt.
 /obj/item/implant/teleport_blocker/proc/on_jaunt(mob/living/jaunter)