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/datums/components/leanable.dm

@@ -105,12 +105,12 @@
 		COMSIG_LIVING_GET_PULLED,
 	), PROC_REF(stop_leaning))
 
-	RegisterSignal(src, COMSIG_MOVABLE_TELEPORTED, PROC_REF(teleport_away_while_leaning))
+	RegisterSignal(src, COMSIG_MOVABLE_POST_TELEPORT, PROC_REF(teleported_away_while_leaning))
 	// RegisterSignal(src, COMSIG_ATOM_POST_DIR_CHANGE, PROC_REF(lean_dir_changed)) // BUBBER EDIT REMOVE - Don't reset leaning on direction change
 	update_fov()
 
 /// You fall on your face if you get teleported while leaning
-/mob/living/proc/teleport_away_while_leaning()
+/mob/living/proc/teleported_away_while_leaning()
 	SIGNAL_HANDLER
 
 	// Make sure we unregister signal handlers and reset animation
@@ -127,7 +127,7 @@
 		COMSIG_LIVING_DISARM_HIT,
 		COMSIG_LIVING_GET_PULLED,
 		COMSIG_ATOM_POST_DIR_CHANGE,
-		COMSIG_MOVABLE_TELEPORTED,
+		COMSIG_MOVABLE_POST_TELEPORT,
 	))
 	remove_offsets(LEANING_TRAIT)
 	remove_traits(list(TRAIT_UNDENSE, TRAIT_EXPANDED_FOV), LEANING_TRAIT)