rpcserver: return total num of fwdPkgs in PendingChannels

This commit adds a new field, NumForwardingPackages, in the
PendingChannels RPC response to specify how many forwarding packages the
channel has.

lnrpc/lightning.proto

@@ -2236,6 +2236,9 @@ message PendingChannelsResponse {
 
         // The commitment type used by this channel.
         CommitmentType commitment_type = 9;
+
+        // Total number of forwarding packages created in this channel.
+        int64 num_forwarding_packages = 10;
     }
 
     message PendingOpenChannel {

lnrpc/lightning.swagger.json

@@ -2698,6 +2698,11 @@
         "commitment_type": {
           "$ref": "#/definitions/lnrpcCommitmentType",
           "description": "The commitment type used by this channel."
+        },
+        "num_forwarding_packages": {
+          "type": "string",
+          "format": "int64",
+          "description": "Total number of forwarding packages created in this channel."
         }
       }
     },

rpcserver.go

@@ -3239,6 +3239,17 @@ func (r *rpcServer) PendingChannels(ctx context.Context,
 			return nil, err
 		}
 
+		// Get the number of forwarding packages from the historical
+		// channel.
+		fwdPkgs, err := historical.LoadFwdPkgs()
+		if err != nil {
+			rpcsLog.Errorf("unable to load forwarding packages "+
+				"for channel:%s, %v",
+				historical.ShortChannelID, err)
+			return nil, err
+		}
+		channel.NumForwardingPackages = int64(len(fwdPkgs))
+
 		closeTXID := pendingClose.ClosingTXID.String()
 
 		switch pendingClose.CloseType {
@@ -3350,16 +3361,25 @@ func (r *rpcServer) PendingChannels(ctx context.Context,
 			)
 		}
 
+		fwdPkgs, err := waitingClose.LoadFwdPkgs()
+		if err != nil {
+			rpcsLog.Errorf("unable to load forwarding packages "+
+				"for channel:%s, %v",
+				waitingClose.ShortChannelID, err)
+			return nil, err
+		}
+
 		channel := &lnrpc.PendingChannelsResponse_PendingChannel{
-			RemoteNodePub:        hex.EncodeToString(pub),
-			ChannelPoint:         chanPoint.String(),
-			Capacity:             int64(waitingClose.Capacity),
-			LocalBalance:         int64(waitingClose.LocalCommitment.LocalBalance.ToSatoshis()),
-			RemoteBalance:        int64(waitingClose.LocalCommitment.RemoteBalance.ToSatoshis()),
-			LocalChanReserveSat:  int64(waitingClose.LocalChanCfg.ChanReserve),
-			RemoteChanReserveSat: int64(waitingClose.RemoteChanCfg.ChanReserve),
-			Initiator:            rpcInitiator(waitingClose.IsInitiator),
-			CommitmentType:       rpcCommitmentType(waitingClose.ChanType),
+			RemoteNodePub:         hex.EncodeToString(pub),
+			ChannelPoint:          chanPoint.String(),
+			Capacity:              int64(waitingClose.Capacity),
+			LocalBalance:          int64(waitingClose.LocalCommitment.LocalBalance.ToSatoshis()),
+			RemoteBalance:         int64(waitingClose.LocalCommitment.RemoteBalance.ToSatoshis()),
+			LocalChanReserveSat:   int64(waitingClose.LocalChanCfg.ChanReserve),
+			RemoteChanReserveSat:  int64(waitingClose.RemoteChanCfg.ChanReserve),
+			Initiator:             rpcInitiator(waitingClose.IsInitiator),
+			CommitmentType:        rpcCommitmentType(waitingClose.ChanType),
+			NumForwardingPackages: int64(len(fwdPkgs)),
 		}
 
 		waitingCloseResp := &lnrpc.PendingChannelsResponse_WaitingCloseChannel{