Ammo Management Overhaul Dev

In Early Testing.

Adds Loose 556 rounds that allow the player to repack mags with
Adds a carryable resupply kit that contains inventory space for loose rounds

TO DO:
empty magazines should be retained when reloading
add a more convenient way to see how many rounds remain in the stack.
update the model to be more easily visible on the ground
Replace repack mag with load round action