fix navigation to artist
somehow, the push is not finished when activated() attached signal handler is called. This results in a second push to be refused (a warning is logged in console):
qrc:/qml/ContentView.qml:210:13: QML StackView: cannot push while already in the process of completing a push
this prevents a second push to happen trly and waits for the StackView to be no longer busy before notifying the end of the push
the same should be added to pop to ensure this will also not break