keybind signal support, ported from TGMC (#52219)

* keybind signal support, ported from TGMC

* Thank you linter

* remove unused and extra defines

* move signal defines up and fix emote keybind runtimes

* Apply suggestions

* Update keybinding.dm

* Missed this one in the upstream merge

* Ignore keybindings without names

* back to the OG

* Update living.dm

* Update living.dm

* got it

* trailing newline

* Update code/datums/keybinding/living.dm

Co-authored-by: Rohesie <rohesie@gmail.com>

Co-authored-by: Rohesie <rohesie@gmail.com>

code/modules/unit_tests/_unit_tests.dm

@@ -15,6 +15,7 @@
 #include "card_mismatch.dm"
 #include "chain_pull_through_space.dm"
 #include "component_tests.dm"
+#include "keybinding_init.dm"
 #include "outfit_sanity.dm"
 #include "plantgrowth_tests.dm"
 #include "reagent_id_typos.dm"

code/modules/unit_tests/keybinding_init.dm

@@ -0,0 +1,6 @@
+/datum/unit_test/keybinding_init/Run()
+	for(var/i in subtypesof(/datum/keybinding))
+		var/datum/keybinding/KB = i
+		if(initial(KB.keybind_signal) || !initial(KB.name))
+			continue
+		Fail("[KB.name] does not have a keybind signal defined.")