Spinny 3D render of BlockCollection / Blueprints

[Cervator]

I'm figuring it would be a nice game element to be able to preview a spinning (or spinnable) collection of blocks likely related to a blueprint. New utility class BlockCollection could probably be involved, I left it with calcWidth/Height/Depth methods to help with predicting the scale at which any arbitrary collection should be shrunk to so differently sized collections can be displayed roughly at the same size.

Exactly how / where the 3D render should be shown - I'm less sure of. Could probably just be in a corner like the old spinny cube, visible when the player has a certain tool (able to eventually scroll through blueprints) equipped. I put a general Debug tool in the meta branch, for now whenever that tool is active it could enable the display of the one predefined PortalBlueprint