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/channelrx/freqtracker/freqtrackerplugin.cpp

@@ -54,8 +54,8 @@ void FreqTrackerPlugin::initPlugin(PluginAPI* pluginAPI)
 
 #ifdef SERVER_MODE
 PluginInstanceGUI* FreqTrackerPlugin::createRxChannelGUI(
-        DeviceUISet *deviceUISet __attribute__((unused)),
-        BasebandSampleSink *rxChannel __attribute__((unused)))
+        DeviceUISet *deviceUISet,
+        BasebandSampleSink *rxChannel)
 {
     return 0;
 }