message: Slight refactoring for logging in AgentUtils
diff: messageCallback:(void (^)(SovrinHandle connectHandle, NSString *message))messageCallback
  outConnectionHandle:(SovrinHandle *)outConnectionHandle
  {
  - // connection callback
  + // connection callback. waiting for completion
  XCTestExpectation* connectCompletionExpectation = [[ XCTestExpectation alloc] initWithDescription: @"listener completion finished"];
  __block NSError *connectionErr;
  __block SovrinHandle tempConnectionHandle;
  +
  void (^onConnectCallback)(NSError*, SovrinHandle) = ^(NSError *error, SovrinHandle connectionHandle) {
  - NSLog(@"OnConnectCallback triggered.");
  + NSLog(@"AgentUtils::connectWithPoolHandle::OnConnectCallback triggered with code: %ld", error.code);
  tempConnectionHandle = connectionHandle;
  connectionErr = error;
  [connectCompletionExpectation fulfill];
  // message callback
  - XCTestExpectation* messageCompletionExpectation = [[ XCTestExpectation alloc] initWithDescription: @"message completion finished"];
  - __block NSError *messageErr;
  void (^onMessageCallback)(SovrinHandle, NSError*, NSString*) = ^(SovrinHandle xConnectionHandle, NSError *error, NSString *message) {
  - NSLog(@"OnMessageCallback triggered invoced with error code: %ld", error.code);
  - messageErr = error;
  + NSLog(@"AgentUtils::connectWithPoolHandle::OnMessageCallback triggered invoced with error code: %ld", error.code);
  if (messageCallback != nil) { messageCallback(xConnectionHandle, message);}
  - [messageCompletionExpectation fulfill];
  };
  NSError *ret = [SovrinAgent connectWithPoolHandle:poolHandle
  // wait for connection callback
  [self waitForExpectations: @[connectCompletionExpectation] timeout:[TestUtils defaultTimeout]];
  - if (connectionErr.code != Success)
  - {
  - NSLog(@"Connection callback returned error code: %ld", connectionErr.code);
  - return connectionErr;
  - }
  if (outConnectionHandle) { *outConnectionHandle = tempConnectionHandle;}
  {
  // connection callback
  void (^onConnectCallback)(SovrinHandle, NSError*, SovrinHandle, NSString*, NSString* ) = ^(SovrinHandle xListenerHandle, NSError *error, SovrinHandle connectionHandle, NSString *senderDid, NSString *receiverDid) {
  - XCTAssertEqual(error.code, Success, @"onConnectCallback in AgentUtiles");
  - NSLog(@"OnConnectCallback triggered with error code: %ld", (long)error.code);
  + NSLog(@"AgentUtils::listen::New connection %@ on listener {}, err {:?}, sender DID {}, receiver DID {}", connectionHandle, xListenerHandle, (long)error.code, senderDid, receiverDid);
  if (connectionCallback) {connectionCallback(xListenerHandle, connectionHandle);}
  };
  // message callback
  void (^onMessageCallback)(SovrinHandle, NSError*, NSString*) = ^(SovrinHandle xConnectionHandle, NSError *error, NSString *message) {
  - NSLog(@"OnMessageCallback triggered with error code: %ld.", (long)error.code);
  + NSLog(@"AgentUtils::listen::On connection %@ received (with error %ld) agent message (CLI->SRV): %@", xConnectionHandle, (long)error.code), message);
  if (messageCallback != nil) { messageCallback(xConnectionHandle, message);}
  };
  