Multiblock Portals

I think the portal system in MCreator needs an overhaul that allows custom shapes and blocks to be used along with conditions for portal activation (not just when clicked with 'flint & steal'). Also, a way for portals to be horizontal. And maybe a way for skybox portals like the ender portal.

Features requested:

-Multiblock portals

-More activation conditions

-Possibility to make skybox portals

-Horizontal portals