Fix compilation on Kubuntu 20.04
-QLatin1String gained .arg() function in Qt 5.14 (> required 5.10) -Qt::SkipEmptyParts was introduced in Qt 5.15 -QList != QVector in Qt < 5.15 ? -Mistakenly removed const variable used inside KF5 5.69 version check -QActionGroup::setExclusionPolicy() was introduced in Qt 5.14 and the enum QActionGroup::ExclusionPolicy::Exclusive is default policy