Refactors sound groups to use decls instead of a massive switch with dozens of global lists. (#9702)

code/modules/mining/mine_items.dm

@@ -69,7 +69,7 @@
 	origin_tech = list(TECH_MATERIAL = 1, TECH_ENGINEERING = 1)
 	attack_verb = list("hit", "pierced", "sliced", "attacked")
 	hitsound = 'sound/weapons/rapidslice.ogg'
-	var/drill_sound = "pickaxe"
+	var/drill_sound = /decl/sound_category/pickaxe_sound
 	var/drill_verb = "excavating"
 	var/autodrill = 0 //pickaxes must be manually swung to mine, drills can mine rocks via bump
 	sharp = TRUE
@@ -78,7 +78,7 @@
 
 	var/excavation_amount = 40
 	var/wielded = FALSE
-	var/wield_sound = "wield_generic"
+	var/wield_sound = /decl/sound_category/generic_wield_sound
 	var/unwield_sound = null
 	var/force_unwielded = 5.0
 	var/force_wielded = 15.0

code/modules/mining/mine_turf_types.dm

@@ -63,7 +63,7 @@
 	canSmoothWith = null
 	openspace_override_type = /turf/simulated/open/chasm/airless
 
-	footstep_sound = "asteroid"
+	footstep_sound = /decl/sound_category/asteroid_footstep
 
 /turf/unsimulated/floor/asteroid/basalt/get_smooth_underlay_icon(mutable_appearance/underlay_appearance, turf/asking_turf, adjacency_dir)
 	underlay_appearance.icon = icon
@@ -92,7 +92,7 @@
 	smooth = SMOOTH_MORE | SMOOTH_BORDER | SMOOTH_NO_CLEAR_ICON
 	base_icon = 'icons/turf/smooth/ash.dmi'
 	base_icon_state = "ash"
-	footstep_sound = "sand"
+	footstep_sound = /decl/sound_category/sand_footstep
 	does_footprint = TRUE
 	footprint_color = COLOR_ASH
 	track_distance = 6

code/modules/mining/mine_turfs.dm

@@ -550,7 +550,7 @@ var/list/mineral_can_smooth_with = list(
 	var/dug = 0 //Increments by 1 everytime it's dug. 11 is the last integer that should ever be here.
 	var/digging
 	has_resources = 1
-	footstep_sound = "gravelstep"
+	footstep_sound = /decl/sound_category/asteroid_footstep
 
 	roof_type = null