[Feature Request] Import other wallet seeds for CJ sweeps only

[RobertMiranda]

An example would be running JoinMarket with Wallet1 as Yield Generator.

Buying coins using Bisq.

Importing the Bisq wallet in JoinMarket as Wallet2 with a recover flag that indicates it's a Bisq wallet to adjust derivation path. Only mixdepth 0 is created. Freezing UTXO's ability.

CJ sweeping the Bisq wallet UTXO(s) out.

[chris-belcher]

This is a lot like the "import private key" feature but importing a seed phrase instead(?) Good idea.

[kristapsk]

I think better way forward is to improve PSBT functionality instead, to be able to import xpub as a watch-only wallet in JM, then generate PSBT using sendpayment and sign it with other wallet. That will anyway be needed to be able to use hardware wallets as a taker using JM tools, see #663.