Adding an Entity Type Tags using Powers

[256smash]

In vanilla minecraft, there are tags in the datapack that affect vanilla mob abilities such as stray which uses "freeze_immune_entity_types" and "skeletons". These entity type tags can be used as powers so the datapack doesn't have to be changed again, for example a player can get the "freeze_hurts_extra_types" tag for themselves and other players and mobs that this can be used for origin.

[MerchantPug]

This is a planned feature for the next update.

Duplicate of #203