App hangs on confirm to withdraw funds
Currently the application is hanging when the user confirms to withdraw funds, because [`wallet.relayTx()`](https://github.com/haveno-dex/haveno/blob/eefcf0191f1a38d5a9441e7bcdbfe2bd845469b2/desktop/src/main/java/haveno/desktop/main/funds/withdrawal/WithdrawalView.java#L287) is being called on the main thread, causing the application to block until the relay completes.

<img width="1272" alt="image" src="https://github.com/haveno-dex/haveno/assets/13068859/82734ec7-5670-4ccd-a30f-c781f4b1df7a">


This issue requests moving the relay off the main thread, disabling the confirm button, and indicating a spinny wheel.