DataPack Filter Fix

Minecraft has data packs, which allow changing things like recipes without
writing a mod. In the data pack, you can set a filter property to remove
files from data packs that appear before it.

Consider this example. This should remove the non_existant_path from the
minecraft namespace and all the recipes from the non_existant_mod.

{
  "pack": {
    "description": {
      "text": "Test pack to reproduce filter error"
    },
    "pack_format": 15
  },
  "filter": {
    "block": [
      {"namespace": "minecraft", "path": "non_existant_path"},
      {"namespace": "non_existant_mod", "path": "recipes"}
    ]
  }
}

However, in Vanilla, it will handle the namespaces and paths separately. This
will cause it to apply both path filters to both namespaces. So in reality, it
will remove all minecraft recipes too.

This mod fixes the handling of the filter attribute so it works as you’d
expect.