lnrpc: display remote peer features via rpc

lnrpc/rpc.proto

@@ -1449,6 +1449,9 @@ message Peer {
 
     // The type of sync we are currently performing with this peer.
     SyncType sync_type = 10 [json_name = "sync_type"];
+
+    /// Features advertised by the remote peer in their init message.
+    repeated Feature features = 11 [json_name = "features"];
 }
 
 message ListPeersRequest {

lnrpc/rpc.swagger.json

@@ -3437,6 +3437,13 @@
         "sync_type": {
           "$ref": "#/definitions/PeerSyncType",
           "description": "The type of sync we are currently performing with this peer."
+        },
+        "features": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/lnrpcFeature"
+          },
+          "description": "/ Features advertised by the remote peer in their init message."
         }
       }
     },