/withdraw request is sent whenever MilfMasters Game Client requests to withdraw (spend) money from players wallet./withdraw request must NOT be called multiple times, but ONLY once!/withdraw request fails for ANY reason, a /rollbackWithdrawal request must be sent, to ensure that also Quantum Web Backend cancels the withdrawal./withdraw request succeed, the caller = MilfMasters Backend, must do any follow-up actions and finalize withdrawal with either /confirmWithdrawal = withdrawal succeed or /rollbackWithdrawal = withdrawal not finished successfully.