test(gossipsub): block5 protobuf test cases (#1204)

Co-authored-by: Radoslaw Kaminski <radoslaw@status.im>

tests/pubsub/testgossipsubmessagehandling.nim

@@ -842,3 +842,34 @@ suite "GossipSub Message Handling":
       publishResult == 0
       results[0].isPending()
       results[1].isPending()
+
+  # check correctly parsed ihave/iwant/graft/prune/idontwant messages
+  # check value before & after decoding equal using protoc cmd tool for reference
+  asyncTest "ControlMessage RPCMsg encoding and decoding":
+    let id: seq[byte] = @[123]
+    let message = RPCMsg(
+      control: some(
+        ControlMessage(
+          ihave: @[ControlIHave(topicID: "foobar", messageIDs: @[id])],
+          iwant: @[ControlIWant(messageIDs: @[id])],
+          graft: @[ControlGraft(topicID: "foobar")],
+          prune: @[ControlPrune(topicID: "foobar", backoff: 10.uint64)],
+          idontwant: @[ControlIWant(messageIDs: @[id])],
+        )
+      )
+    )
+    #data encoded using protoc cmd tool
+    let expectedEncoded: seq[byte] =
+      @[
+        26, 45, 10, 11, 10, 6, 102, 111, 111, 98, 97, 114, 18, 1, 123, 18, 3, 10, 1,
+        123, 26, 8, 10, 6, 102, 111, 111, 98, 97, 114, 34, 10, 10, 6, 102, 111, 111, 98,
+        97, 114, 24, 10, 42, 3, 10, 1, 123,
+      ]
+
+    let actualEncoded = encodeRpcMsg(message, true)
+    check:
+      actualEncoded == expectedEncoded
+
+    let actualDecoded = decodeRpcMsg(expectedEncoded).value
+    check:
+      actualDecoded == message