swapserverrpc: refactor reservation notifications

This commit refactors the proto definitions of the
reservation notifications to use a more generic
mechanism that can be used for other types of
notifications as well.

Author: sputn1ck

swapserverrpc/reservation.pb.go

@@ -9,11 +9,6 @@ package looprpc;
 option go_package = "github.com/lightninglabs/loop/swapserverrpc";
 
 service ReservationService {
-    // ReservationNotificationStream is a server side stream that sends
-    // notifications if the server wants to open a reservation to the client.
-    rpc ReservationNotificationStream (ReservationNotificationRequest)
-        returns (stream ServerReservationNotification);
-
     // OpenReservation requests a new reservation UTXO from the server.
     rpc OpenReservation (ServerOpenReservationRequest)
         returns (ServerOpenReservationResponse);
@@ -22,6 +17,8 @@ service ReservationService {
 // ReservationNotificationRequest is an empty request sent from the client to
 // the server to open a stream to receive reservation notifications.
 message ReservationNotificationRequest {
+    // protocol_version is the maximum version the client supports.
+    ReservationProtocolVersion protocol_version = 1;
 }
 
 // ServerReservationNotification is a notification sent from the server to the
@@ -64,7 +61,7 @@ enum ReservationProtocolVersion {
     // protocol version is not set.
     RESERVATION_NONE = 0;
 
-    // RESERVATION_SERVER_REQUEST is the first version of the reservation
+    // RESERVATION_SERVER_NOTIFY_FULL is the first version of the reservation
     // protocol where the server notifies the client about a reservation.
     RESERVATION_SERVER_NOTIFY = 1;
 };