multi: expand SendOutputs and CreateSimpleTx to take utxos

This commit updates the interface methods from
`lnwallet.WalletController` to take optional input set which can be used
to create the tx.

lnwallet/rpcwallet/rpcwallet.go

@@ -22,6 +22,7 @@ import (
 	"github.com/btcsuite/btcd/wire"
 	"github.com/btcsuite/btcwallet/waddrmgr"
 	basewallet "github.com/btcsuite/btcwallet/wallet"
+	"github.com/lightningnetwork/lnd/fn"
 	"github.com/lightningnetwork/lnd/input"
 	"github.com/lightningnetwork/lnd/keychain"
 	"github.com/lightningnetwork/lnd/lncfg"
@@ -120,12 +121,13 @@ func (r *RPCKeyRing) NewAddress(addrType lnwallet.AddressType, change bool,
 // NOTE: This is a part of the WalletController interface.
 //
 // NOTE: This method only signs with BIP49/84 keys.
-func (r *RPCKeyRing) SendOutputs(outputs []*wire.TxOut,
-	feeRate chainfee.SatPerKWeight, minConfs int32, label string,
+func (r *RPCKeyRing) SendOutputs(inputs fn.Set[wire.OutPoint],
+	outputs []*wire.TxOut, feeRate chainfee.SatPerKWeight,
+	minConfs int32, label string,
 	strategy basewallet.CoinSelectionStrategy) (*wire.MsgTx, error) {
 
 	tx, err := r.WalletController.SendOutputs(
-		outputs, feeRate, minConfs, label, strategy,
+		inputs, outputs, feeRate, minConfs, label, strategy,
 	)
 	if err != nil && err != basewallet.ErrTxUnsigned {
 		return nil, err