Send the configuration from plugin to Wine host

Next we can add some options for different plugin editor behaviours for #27.

src/wine-host/bridges/vst2.cpp

@@ -134,6 +134,10 @@ Vst2Bridge::Vst2Bridge(boost::asio::io_context& main_context,
     // `audioMasterIOChanged()`.
     write_object(host_vst_control, EventResult{0, *plugin, std::nullopt});
 
+    // After sending the AEffect struct we'll receive this instance's
+    // configuration as a response
+    config = read_object<Configuration>(host_vst_control);
+
     // This works functionally identically to the `handle_dispatch()` function,
     // but this socket will only handle MIDI events and it will handle them
     // eagerly. This is needed because of Win32 API limitations.

src/wine-host/bridges/vst2.h

@@ -29,6 +29,7 @@
 #include <boost/asio/local/stream_protocol.hpp>
 #include <mutex>
 
+#include "../../common/configuration.h"
 #include "../../common/logging.h"
 #include "../editor.h"
 #include "../utils.h"
@@ -167,6 +168,13 @@ class Vst2Bridge {
      */
     boost::asio::io_context& io_context;
 
+    /**
+     * The configuration for this instance of yabridge based on the `.so` file
+     * that got loaded by the host. This configuration gets loaded on the plugin
+     * side, and then sent over to the Wine host as part of the startup process.
+     */
+    Configuration config;
+
     /**
      * The shared library handle of the VST plugin. I sadly could not get
      * Boost.DLL to work here, so we'll just load the VST plugisn by hand.