Targeting Datums Renamed (and global) (#79513)

## About The Pull Request

[Implements the backend required to make targeting datums
global](https://github.com/tgstation/tgstation/commit/6901ead12e419530b7f646ea21094d4432d7385e)

It's inconsistent with the rest of basic ai for these to have a high
degree of state, plus like, such a waste yaknow?

[Implements
GET_TARGETING_STRATEGY](https://github.com/tgstation/tgstation/commit/d79c29134d03424a9f8bacd64c08cb41775fe8c0)

Regexes used:
new.*(/datum/targetting_datum[^,(]*)\(*\)* -> GET_TARGETING_STRATEGY($1)

Renamed all instances of targetting to targeting (also targetting datum
-> targeting strategy)

I've used GET_TARGETING_STRATEGY at the source where the keys are
actually used, rather then in the listing. This works out just fine.

## Why It's Good For The Game

Not a misspelled name through the whole codebase, very slightly less
memory load for basically no downside (slight cpu cost maybe but not a
significant one.

---------

Co-authored-by: John Willard <53777086+JohnFulpWillard@users.noreply.github.com>

code/modules/mob/living/basic/tree.dm

@@ -100,7 +100,7 @@
 
 /datum/ai_controller/basic_controller/tree
 	blackboard = list(
-		BB_TARGETTING_DATUM = new /datum/targetting_datum/basic(),
+		BB_TARGETING_STRATEGY = /datum/targeting_strategy/basic,
 	)
 
 	ai_movement = /datum/ai_movement/basic_avoidance