launcher: configure and preview DualSense lightbar color (#912)

launcher: configure and preview controller lightbar color

Add an optional lightbar color to launcher settings and pass it to the emulator with --controller-color. Preview changes on RGB gamepads, handle controller hotplug events, and restore the saved color when settings dialogs close. Release launcher preview handles when starting a game.

Co-authored-by: m66401970-eng <m66401970@gmail.com>

src/common/emulatorConfig.cpp

@@ -47,6 +47,10 @@ const std::string& GetAudioInputDevice() {
 	return g_config->audio_input_device;
 }
 
+const std::optional<ControllerColor>& GetControllerColor() {
+	return g_config->controller_color;
+}
+
 PresentMode GetPresentMode() {
 	return g_config->present_mode;
 }