Improve calls panel in macOS.

Use Qt::Dialog instead of Qt::Tool which works better with window
activation / deactivation handling.

Stop displaying the panel on all spaces when the call is established.

Telegram/SourceFiles/platform/linux/specific_linux.cpp

@@ -377,10 +377,7 @@ void finish() {
 	_psEventFilter = nullptr;
 }
 
-void SetWatchingMediaKeys(bool watching) {
-}
-
-bool TransparentWindowsSupported(QPoint globalPosition) {
+bool TranslucentWindowsSupported(QPoint globalPosition) {
 	if (auto app = static_cast<QGuiApplication*>(QCoreApplication::instance())) {
 		if (auto native = app->platformNativeInterface()) {
 			if (auto desktop = QApplication::desktop()) {
@@ -405,9 +402,6 @@ bool TransparentWindowsSupported(QPoint globalPosition) {
 	return false;
 }
 
-void InitOnTopPanel(QWidget *panel) {
-}
-
 namespace ThirdParty {
 
 void start() {