Moves an item from this inventory into another - no world drop, no destroy. The usual gates get a say (Sandbox.BaseInventoryComponent.OnRemoving(Sandbox.BaseInventoryItem) here, Sandbox.BaseInventoryComponent.OnAdding(Sandbox.BaseInventoryItem,System.Int32) and the item's own say there); any refusal leaves everything as it was. Reserve ammo stays behind - the pool lives on the inventory, not the item. The destination doesn't auto-deploy (it may be a chest). Host only - who may move items between which inventories is game policy, so games route their own requests here. Returns whether the item moved.