lnrpc+itest: return channel Memo for Pending channels

In a previous PR we added a Memo field for channels that could be
specified when opening a channel. This was a reference note-to-self
with no bearing on the functioning of the channel. In that PR, the
memo value was returned only through ListChannels. This commit builds
upon that PR by also returning the Memo field for channels returned by
PendingChannels RPC.

itest/lnd_onchain_test.go

@@ -459,6 +459,7 @@ func testAnchorThirdPartySpend(ht *lntest.HarnessTest) {
 	const (
 		firstChanSize   = 1_000_000
 		anchorFeeBuffer = 500_000
+		testMemo        = "bob is a good peer"
 	)
 	ht.FundCoins(firstChanSize+anchorFeeBuffer, alice)
 
@@ -466,7 +467,8 @@ func testAnchorThirdPartySpend(ht *lntest.HarnessTest) {
 	// fully.
 	aliceChanPoint1 := ht.OpenChannel(
 		alice, bob, lntest.OpenChannelParams{
-			Amt: firstChanSize,
+			Amt:  firstChanSize,
+			Memo: testMemo,
 		},
 	)
 
@@ -509,6 +511,12 @@ func testAnchorThirdPartySpend(ht *lntest.HarnessTest) {
 	// PendingChannels RPC under the waiting close section.
 	waitingClose := ht.AssertChannelWaitingClose(alice, aliceChanPoint1)
 
+	// Verify that the channel Memo is returned even for channels that are
+	// waiting close (close TX broadcasted but not confirmed)
+	pendingChannelsResp := alice.RPC.PendingChannels()
+	require.Equal(ht, testMemo,
+		pendingChannelsResp.WaitingCloseChannels[0].Channel.Memo)
+
 	// At this point, the channel is waiting close, and we have both the
 	// commitment transaction and anchor sweep in the mempool.
 	const expectedTxns = 2
@@ -531,6 +539,12 @@ func testAnchorThirdPartySpend(ht *lntest.HarnessTest) {
 	// on the number of anchor channels.
 	ht.AssertChannelPendingForceClose(alice, aliceChanPoint1)
 
+	// Verify that the channel Memo is returned even for channels that are
+	// pending force close (close TX confirmed but sweep hasn't happened)
+	pendingChannelsResp = alice.RPC.PendingChannels()
+	require.Equal(ht, testMemo,
+		pendingChannelsResp.PendingForceClosingChannels[0].Channel.Memo)
+
 	// With the anchor output located, and the main commitment mined we'll
 	// instruct the wallet to send all coins in the wallet to a new address
 	// (to the miner), including unconfirmed change.