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/interface.go

@@ -413,8 +413,7 @@ type WalletController interface {
 	//
 	// NOTE: This method requires the global coin selection lock to be held.
 	LeaseOutput(id wtxmgr.LockID, op wire.OutPoint,
-		duration time.Duration) (time.Time, []byte, btcutil.Amount,
-		error)
+		duration time.Duration) (time.Time, error)
 
 	// ReleaseOutput unlocks an output, allowing it to be available for coin
 	// selection if it remains unspent. The ID should match the one used to