imp: emit defaults when marshalling clienttypes.Height to json (#6640)

Co-authored-by: Carlos Rodriguez <[email protected]>

proto/ibc/core/client/v1/client.proto

@@ -44,14 +44,17 @@ message ClientConsensusStates {
 // breaking changes In these cases, the RevisionNumber is incremented so that
 // height continues to be monitonically increasing even as the RevisionHeight
 // gets reset
+//
+// Please note that json tags for generated Go code are overridden to explicitly exclude the omitempty jsontag.
+// This enforces the Go json marshaller to always emit zero values for both revision_number and revision_height.
 message Height {
   option (gogoproto.goproto_getters)  = false;
   option (gogoproto.goproto_stringer) = false;
 
   // the revision that the client is currently on
-  uint64 revision_number = 1;
+  uint64 revision_number = 1 [(gogoproto.jsontag) = "revision_number"];
   // the height within the given revision
-  uint64 revision_height = 2;
+  uint64 revision_height = 2 [(gogoproto.jsontag) = "revision_height"];
 }
 
 // Params defines the set of IBC light client parameters.