mulit: remove ListLeasedOutputs in LeaseOutput

This commit removes the call toe `ListLeasedOutputs` in `LeaseOutput` -
the returned info from `ListLeasedOutputs` can easily be accessed via
`FetchInputInfo` and this info is only used at one callsite.
`ListLeasedOutputs` then becomes unnecessary here, plus it's very slow
and needs to be refactored in `btcwallet` instead.

lnwallet/chanfunding/wallet_assembler.go

@@ -525,7 +525,7 @@ func (w *WalletAssembler) ProvisionChannel(r *Request) (Intent, error) {
 		for _, coin := range selectedCoins {
 			outpoint := coin.OutPoint
 
-			_, _, _, err = w.cfg.CoinLeaser.LeaseOutput(
+			_, err = w.cfg.CoinLeaser.LeaseOutput(
 				LndInternalLockID, outpoint,
 				DefaultReservationTimeout,
 			)