[XMP] Fixed issue with xmp_default_volume not being correctly applied

- Added menu to modify XMP volume and state

src/xenia/app/emulator_window.h

@@ -93,6 +93,7 @@ class EmulatorWindow {
                  const xe::ui::RawImage& image);
 
   void ToggleProfilesConfigDialog();
+  void ToggleXMPConfigDialog();
   void SetHotkeysState(bool enabled) { disable_hotkeys_ = !enabled; }
 
   // Types of button functions for hotkeys.
@@ -208,6 +209,24 @@ class EmulatorWindow {
     EmulatorWindow& emulator_window_;
   };
 
+  class XMPConfigDialog final : public ui::ImGuiDialog {
+   public:
+    XMPConfigDialog(ui::ImGuiDrawer* imgui_drawer,
+                    EmulatorWindow& emulator_window)
+        : ui::ImGuiDialog(imgui_drawer), emulator_window_(emulator_window) {
+      if (emulator_window_.emulator_->audio_media_player()) {
+        volume_ = emulator_window_.emulator_->audio_media_player()->GetVolume();
+      }
+    }
+
+   protected:
+    void OnDraw(ImGuiIO& io) override;
+
+   private:
+    EmulatorWindow& emulator_window_;
+    float volume_ = 0.0f;
+  };
+
   explicit EmulatorWindow(Emulator* emulator,
                           ui::WindowedAppContext& app_context, uint32_t width,
                           uint32_t height);
@@ -294,6 +313,8 @@ class EmulatorWindow {
   // messages back to guest.
   std::unique_ptr<ProfileConfigDialog> profile_config_dialog_;
 
+  std::unique_ptr<XMPConfigDialog> xmp_config_dialog_;
+
   std::vector<RecentTitleEntry> recently_launched_titles_;
 };