Cash-in trade

Cash-in (i.e. "remove money") from a trade. Funds are first removed from the trade's PL (if any), then from the trade's margin. Note that cashing-in increases the trade's leverage; the whole margin hence isn't available since leverage is bounded.

{
  "id": "d0b9f9a0-4f6e-4a5a-8b7a-7f0f5f9a8a1e",
  "amount": 100
}