Fixed direct-send RPC-API to accept list of UTXOs

[amitx13]

This PR fixes #1712 and addresses joinmarket-webui/jam#772
Changes Made:

1. Updated the direct-send API to accept a list of UTXOs specified by the user.
2. Implemented backend logic to handle the selection of these UTXOs for the transaction.
3. Added necessary validation checks to ensure the specified UTXOs are part of the user's wallet and are unfrozen.

[amitx13]

Thank you for the feedback. I will ensure the RPC-API maintains backwards compatibility and update the documentation as well.

[amitx13]

Hey @kristapsk I am done with the requested changes. Could you please take a look when you have a moment 🙏

[amitx13]

Hey @kristapsk if you have a moment, could you please take a look at docs/api/wallet-rpc.yaml I tried everything from my side but still, OpenAPI Diff keeps failing. It will be a great help for me as well as for JAM and JoinMarket users

[kristapsk]

Hey @kristapsk if you have a moment, could you please take a look at docs/api/wallet-rpc.yaml I tried everything from my side but still, OpenAPI Diff keeps failing. It will be a great help for me as well as for JAM and JoinMarket users

I'm quite busy with other stuff currently, but will try to take a look at some point, if you will not be able to solve that yourself.