Basic blob mobs (#78520)

## About The Pull Request

I remembered today that blob code is ass, especially blob spores.
There's still a lot to improve but I cleaned up _some_ of it by
converting these mobs.
Now they use a newer framework and more signal handling as compared to
circular references.

I _expect_ the behaviour here to largely be the same as it was or
similar. I haven't added anything fancy or new.

This is a reasonably big PR but at least all of the files are small?
Everything here touched every other thing enough that it didnt make
sense to split up sorry.

Other things I did in code:
- Experimented with replacing the `mob/blob` subtype with a component.
Don't know if this is genius or stupid.
- AI subtree which just walks somewhere. We've used this behaviour a lot
but never given it its own subtree.
- Blob Spores and Zombies are two different mobs now instead of being
one mob which just changes every single one of its properties.
- Made a few living defence procs call super, because the only thing
super does was send a signal and we weren't doing that for no reason.
Also added a couple extra signals for intercepts we did not have.

## Changelog

🆑
fix: Blob spores will respond to rallies more reliably (it won't runtime
every time they try and pathfind).
fix: Blobbernaut pain animation overlays should align with the direction
the mob is facing instead of always facing South
refactor: Blob spores, zombies, and blobbernauts now all use the basic
mob framework. They should work the same, but please report any issues.
/🆑

---------

Co-authored-by: MrMelbert <51863163+MrMelbert@users.noreply.github.com>
Co-authored-by: san7890 <the@san7890.com>

code/datums/ai/basic_mobs/basic_ai_behaviors/travel_towards.dm

@@ -6,6 +6,8 @@
 /datum/ai_behavior/travel_towards
 	required_distance = 0
 	behavior_flags = AI_BEHAVIOR_REQUIRE_MOVEMENT | AI_BEHAVIOR_CAN_PLAN_DURING_EXECUTION
+	/// If true we will get rid of our target on completion
+	var/clear_target = FALSE
 
 /datum/ai_behavior/travel_towards/setup(datum/ai_controller/controller, target_key)
 	. = ..()
@@ -16,7 +18,15 @@
 
 /datum/ai_behavior/travel_towards/perform(seconds_per_tick, datum/ai_controller/controller, target_key)
 	. = ..()
-	finish_action(controller, TRUE)
+	finish_action(controller, TRUE, target_key)
+
+/datum/ai_behavior/travel_towards/finish_action(datum/ai_controller/controller, succeeded, target_key)
+	. = ..()
+	if (clear_target)
+		controller.clear_blackboard_key(target_key)
+
+/datum/ai_behavior/travel_towards/stop_on_arrival
+	clear_target = TRUE
 
 /**
  * # Travel Towards Atom

code/datums/ai/basic_mobs/basic_subtrees/travel_to_point.dm

@@ -0,0 +1,18 @@
+/// Simply walk to a location
+/datum/ai_planning_subtree/travel_to_point
+	/// Blackboard key where we travel a place we walk to
+	var/location_key = BB_TRAVEL_DESTINATION
+	/// What do we do in order to travel
+	var/travel_behaviour = /datum/ai_behavior/travel_towards
+
+/datum/ai_planning_subtree/travel_to_point/SelectBehaviors(datum/ai_controller/controller, seconds_per_tick)
+	. = ..()
+	var/atom/target = controller.blackboard[location_key]
+	if (QDELETED(target))
+		return
+	controller.queue_behavior(travel_behaviour, location_key)
+	return SUBTREE_RETURN_FINISH_PLANNING
+
+
+/datum/ai_planning_subtree/travel_to_point/and_clear_target
+	travel_behaviour = /datum/ai_behavior/travel_towards/stop_on_arrival