Conveyor Belts

Replaced models for up and down slopes from blocky to smooth. Block versions will be available through a resource pack.

Fixed bug where top half of sloped belt would move player when bottom half not enabled.

Fixed a visual bug where fully saturated downward sloping belts would not display the item's movement progress correctly as would sometimes use the fully completed progress of the item before.

Removed unused mixin reference from fabric.mod.json

Items displayed on sloped belts match gradient

When placing downward sloping belts towards self, they will be placed from the top half

Fixed bug where placing sloped belts could remove blocks above them

BlockItem into own class for future changes (rendering direction belt will be placed while holding)