Use the styles default delay for tooltips

This makes them less annoying when scrolling or accessing the popup
menu.

See also #860

src/ui/NhekoGlobalObject.cpp

@@ -4,7 +4,9 @@
 
 #include "NhekoGlobalObject.h"
 
+#include <QApplication>
 #include <QDesktopServices>
+#include <QStyle>
 #include <QUrl>
 #include <QWindow>
 
@@ -75,6 +77,12 @@ Nheko::theme() const
     return Theme(UserSettings::instance()->theme());
 }
 
+int
+Nheko::tooltipDelay() const
+{
+    return QApplication::style()->styleHint(QStyle::StyleHint::SH_ToolTip_WakeUpDelay);
+}
+
 void
 Nheko::openLink(QString link) const
 {