Beta - Vanilla

anvil.beta.vanilla

Experimental vanilla content: ids Mojang's metadata lists that need an experiment toggle in game, and the features.experimental flag in anvilconfig.json to pass Anvil's vanilla id checks. Mirrors anvil.api.vanilla, such as anvil.beta.vanilla.blocks.MinecraftBlockTypes. Kept by hand: tools/update_vanilla.py writes them back into anvil.api.vanilla, so move new experimental ids here after a run.