fix windows code to build with MSVC

- remove __attribute__((unused)) not supported on MSVC
- remove  __attribute((unused)) not supported on MSVC
- add symbol exports to RemoteDataReadQueue and RemoteDataQueue
- add export symbols to sdrsrv

plugins/channeltx/udpsource/udpsourceplugin.cpp

@@ -56,8 +56,8 @@ void UDPSourcePlugin::initPlugin(PluginAPI* pluginAPI)
 
 #ifdef SERVER_MODE
 PluginInstanceGUI* UDPSourcePlugin::createTxChannelGUI(
-        DeviceUISet *deviceUISet __attribute__((unused)),
-        BasebandSampleSource *txChannel __attribute__((unused)))
+        DeviceUISet *deviceUISet,
+        BasebandSampleSource *txChannel)
 {
     return 0;
 }