VST3: Create the window with the plugin-returned initial size

Instead of creating the window as 128x128 and then resizing, create it
with the size requested by the plugin. Fixes Korg VST3 plugins.

src/wine-host/bridges/vst3.cpp

@@ -799,9 +799,16 @@ void Vst3Bridge::run() {
                 // be done in the main UI thread
                 return main_context_
                     .run_in_context([&, &instance = instance]() -> tresult {
+                        Steinberg::ViewRect size;
+                        std::optional<Size> initial_size;
+                        if (instance.plug_view_instance->plug_view->getSize(
+                                &size) == Steinberg::kResultOk) {
+                            initial_size.emplace(size.getWidth(),
+                                                 size.getHeight());
+                        }
                         Editor& editor_instance = instance.editor.emplace(
-                            main_context_, config_, generic_logger_,
-                            x11_handle);
+                            main_context_, config_, generic_logger_, x11_handle,
+                            std::nullopt, initial_size);
                         const tresult result =
                             instance.plug_view_instance->plug_view->attached(
                                 editor_instance.win32_handle(), type.c_str());

src/wine-host/editor.cpp

@@ -256,12 +256,13 @@ Editor::Editor(MainContext& main_context,
                const Configuration& config,
                Logger& logger,
                const size_t parent_window_handle,
-               std::optional<fu2::unique_function<void()>> timer_proc)
+               std::optional<fu2::unique_function<void()>> timer_proc,
+               std::optional<Size> initial_size)
     : use_force_dnd_(config.editor_force_dnd),
       logger_(logger),
       x11_connection_(xcb_connect(nullptr, nullptr), xcb_disconnect),
       dnd_proxy_handle_(WineXdndProxy::get_handle()),
-      wrapper_window_size_({128, 128}),
+      wrapper_window_size_(initial_size.value_or(Size(128, 128))),
       host_window_config_({}),
       parent_window_config_({}),
       // Create a window without any decoratiosn for easy embedding. The

src/wine-host/editor.h

@@ -194,7 +194,8 @@ class Editor {
         const Configuration& config,
         Logger& logger,
         const size_t parent_window_handle,
-        std::optional<fu2::unique_function<void()>> timer_proc = std::nullopt);
+        std::optional<fu2::unique_function<void()>> timer_proc = std::nullopt,
+        std::optional<Size> initial_size = std::nullopt);
 
     /**
      * Resize the `wrapper_window_` to this new size. We need to manually call