[Feature request] Add support for MineClone's container groups.

[ThePython10110]

This mod should support MineClone's container groups. This would make it compatible with any containers that support MineClone's hoppers (and therefore most mods that support MineClone).

From MineClone's GROUPS.md:

• container: Node is a container which physically stores items within and has at least 1 inventory
  • container=2: Has one inventory with list name "main". Items can be placed and taken freely
  • container=3: Same as container=2, but shulker boxes can not be inserted
  • container=4: Furnace-like, has lists "src", "fuel" and "dst".
    It is expected that this also reacts on on_timer;
    the node timer must be started from other mods when they add into "src" or "fuel"
  • container=5: Left part of a 2-part horizontal connected container. Both parts have a "main" inventory
    list. Both inventories are considered to belong together. This is used for large chests.
  • container=6: Same as above, but for the right part.
  • container=7: Has inventory list "main", no movement allowed
  • container=1: Other/unspecified container type

You could do this fairly easily, something like this:

-- This pretty much makes it so that anything that works with MineClone hoppers will
-- automatically work with other hoppers.

hopper:add_container({
	{"top", "group:container=2", "main"},
	{"bottom", "group:container=2", "main"},
	{"side", "group:container=2", "main"},
})

-- The mod already checks the `allow_metadata_inventory_<whatever>` functions, so this works.
hopper:add_container({
	{"top", "group:container=3", "main"},
	{"bottom", "group:container=3", "main"},
	{"side", "group:container=3", "main"},
})

hopper:add_container({
	{"top", "group:container=4", "dst"},
	{"side", "group:container=4", "fuel"},
	{"bottom", "group:container=4", "src"},
})

-- Hoppers will only be able to insert into one side of a double chest (I think); maybe do something about this.
hopper:add_container({
	{"top", "group:container=5", "main"},
	{"bottom", "group:container=5", "main"},
	{"side", "group:container=5", "main"},
})
hopper:add_container({
	{"top", "group:container=6", "main"},
	{"bottom", "group:container=6", "main"},
	{"side", "group:container=6", "main"},
})

[ThePython10110]

MineClone2 has now changed their container groups to be almost meaningless, and they have a new API system that would be quite a bit harder to port. Mineclonia still uses this system, though. It would be great if both were supported, but if only the container groups are added, that's fine with me.