Items always spawn motionless

[floral-qua-floral]

When items are spawned by any means other than being dropped by a player, they always start out completely motionless. This includes items fired from a Dropper, items ejected when a container is destroyed, items dropped when a mob dies, items bartered from Piglins, and likely all other ways an item entity can be spawned. I have also confirmed that the issue occurs with modded item-dispensing, such as when the copper pipes from Simple Copper Pipes eject an item.

Expected behaviour: Items spawn with initial velocity identical to what they would have in vanilla, and then continue to move according to Rayon's physics
Observed behaviour: Items spawn motionless. Items dropped by mobs sometimes appear to have random motion, but this is only because they spawn clipped into the ground and get some motion as they are ejected.
Proposed solution: When an item spawns, it uses the vanilla Motion tag for its initial physics velocity

I've recorded a short video demonstrating the issue:
https://user-images.githubusercontent.com/49110090/182753533-0f8fd957-5b7a-4226-87d4-99555f89563a.mp4

[ethanejohnsons]

In dropz 2.1.1, items should now spawn with the same velocity as vanilla minecraft. It might not look 100% the same as vanilla Minecraft, but it should be much closer than before.