Integrate more with MineClone's APIs

I wasn't sure if their licenses allowed me, but apparently they do:
https://git.minetest.land/MineClone2/MineClone2/issues/1849

.luacheckrc

@@ -1,7 +1,8 @@
 std = "min"
 read_globals = {
-	"default", "digiline", "ItemStack", "mesecon", "minetest", "pipeworks",
-	"table.copy", "table.unpack", "unpack", "VoxelArea", "vector",
+	"default", "digiline", "ItemStack", "mcl_sounds", "mesecon", "minetest",
+	"pipeworks", "table.copy", "table.unpack", "unpack", "VoxelArea",
+	"vector",
 }
 globals = {"minetest.is_protected"}
 ignore = {"21/_.*"}

mod.conf

@@ -2,5 +2,5 @@ name = area_containers
 title = Area Containers
 author = Jude Melton-Houghton
 description = Adds nodes that contain areas in which you can build
-optional_depends = default, digilines, mcl_core, mesecons, mesecons_mvps, pipeworks
+optional_depends = default, digilines, mcl_core, mcl_sounds, mesecons, mesecons_mvps, pipeworks
 min_minetest_version = 5.4

nodes.lua

@@ -108,7 +108,11 @@ for i, name in ipairs(ALL_CONTAINER_STATES) do
 		description = S("Area Container"),
 		tiles = table.copy(container_tiles),
 		drop = ALL_CONTAINER_STATES[1],
-		groups = merged_table(container_pipeworks.groups, {cracky = 2}),
+		groups = merged_table(container_pipeworks.groups, {
+			cracky = 2,
+			pickaxey = 2,
+		}),
+		_mcl_hardness = 5,
 		on_construct = container_base.on_construct,
 		after_place_node = container_after_place_node,
 		on_destruct = container_base.on_destruct,
@@ -143,6 +147,9 @@ for i, name in ipairs(ALL_CONTAINER_STATES) do
 	if minetest.global_exists("default") and
 	   default.node_sound_metal_defaults then
 		container_def.sounds = default.node_sound_metal_defaults()
+	elseif minetest.global_exists("mcl_sounds") and
+	       mcl_sounds.node_sound_metal_defaults then
+		container_def.sounds = mcl_sounds.node_sound_metal_defaults()
 	end
 	if i > 1 then
 		container_def.groups.not_in_creative_inventory = 1