Adds unit test to check for spritesheet issues (tgstation#70351)

* Adds a new spritesheet unit test to catch edge-cases that caused problems in the past.

code/modules/unit_tests/_unit_tests.dm

@@ -169,6 +169,7 @@
 #include "spell_mindswap.dm"
 #include "spell_names.dm"
 #include "spell_shapeshift.dm"
+#include "spritesheets.dm"
 #include "stack_singular_name.dm"
 #include "stomach.dm"
 #include "strippable.dm"

code/modules/unit_tests/achievements.dm

@@ -9,3 +9,5 @@
 		var/init_icon = initial(award.icon)
 		if(!init_icon || !(init_icon in award_icons))
 			TEST_FAIL("Award [initial(award.name)] has an unexistent icon: \"[init_icon || "null"]\"")
+		if(length(initial(award.database_id)) > 32) //sql schema limit
+			TEST_FAIL("Award [initial(award.name)] database id is is too long")

code/modules/unit_tests/spritesheets.dm

@@ -0,0 +1,11 @@
+///Checks if spritesheet assets contain icon states with invalid names
+/datum/unit_test/spritesheets
+
+/datum/unit_test/spritesheets/Run()
+	for(var/datum/asset/spritesheet/sheet as anything in subtypesof(/datum/asset/spritesheet))
+		if(!initial(sheet.name)) //Ignore abstract types
+			continue
+		sheet = get_asset_datum(sheet)
+		for(var/sprite_name in sheet.sprites)
+			if(!sprite_name)
+				TEST_FAIL("Spritesheet [sheet.type] has a nameless icon state.")