Per world for entity can use portals

[IceWaffles]

Allow use of per world configuration for the option entities-can-use-portals in purpur.yml. For example, if that option is only disabled for the end, then entities (apart from players, obviously) can only not use end portal to go back into the overworld, but entities can still pass through nether portals from the overworld to the nether, as that option is not disabled for the overworld.

[BillyGalbreath]

It's already a per-world setting...