(Bedrock Parity) Spawn Rules

Add spawn rules from Bedrock Edition. Remove spawners property from biomes.

Example spawn rules for the zombie:

{
  "description": {
    "identifier": "minecraft:zombie",
    "population_control": "monster"
  },
  "conditions": [
    {
      "minecraft:spawns_on_surface": {},
      "minecraft:brightness_filter": {
        "min": 0,
        "max": 0,
        "adjust_for_weather": true
      },
      "minecraft:difficulty_filter": {
        "min": "easy",
        "max": "hard"
      },
      "minecraft:weight": {
        "default": 100
      },
      "minecraft:herd": {
        "min_size": 2,
        "max_size": 4
      },
      "minecraft:permute_type": [
        {
          "weight": 95
        },
        {
          "weight": 5,
          "entity_type": "minecraft:zombie_villager"
        }
      ],
    }
  ]
  "biomes": "#minecraft:has_entity/zombie"
}