bindable action buttons (#81371)

## About The Pull Request
### work started 12/12/2023


you may alt-click action buttons to bind them to a key
these are subject to click cooldown and if an action successfully
triggers click cooldown is triggered so you cant instantly do multiple
alt-click again to unbind
## Why It's Good For The Game

moving your mouse to the top left corner to do combat is not good
gameplay

## Changelog
🆑
qol: you may altclick action buttons to bind them to a key
/🆑

---------

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

code/modules/keybindings/bindings_client.dm

@@ -75,11 +75,10 @@
 		if(kb.can_use(src) && kb.down(src) && keycount >= MAX_COMMANDS_PER_KEY)
 			break
 
-	holder?.key_down(_key, src)
-	mob.focus?.key_down(_key, src)
+	holder?.key_down(_key, src, full_key)
+	mob.focus?.key_down(_key, src, full_key)
 	mob.update_mouse_pointer()
 
-
 /client/verb/keyUp(_key as text)
 	set instant = TRUE
 	set hidden = TRUE

code/modules/keybindings/setup.dm

@@ -1,6 +1,7 @@
 // Set a client's focus to an object and override these procs on that object to let it handle keypresses
 
-/datum/proc/key_down(key, client/user) // Called when a key is pressed down initially
+/datum/proc/key_down(key, client/user, full_key) // Called when a key is pressed down initially
+	SHOULD_CALL_PARENT(TRUE)
 	return
 /datum/proc/key_up(key, client/user) // Called when a key is released
 	return