Revert "Add a quick change menu to the playlist container."

This reverts commit 1cddc696ae6192d18d9006ea26744ed905053abe.

Conflicts:
	src/ui/behavioursettingspage.ui
Revert "Finished the changes to the quick change menu. Everything should work."

This reverts commit a468085c3ae18547a0c27f043ee32fc998087bb5.

Conflicts:
	src/playlist/playlistcontainer.cpp
	src/playlist/playlistcontainer.h
	src/ui/behavioursettingspage.cpp
Missing things from previous commit
Reuse some work from Alan from pull request #4484
Fix member not initialized in constructor.
Was init soon after anyway, but FWIW...
Use a save dialog option instead of quick change menu.
This is less confusing IMO. The dialog will shown up only if users decided to in the preferences, so that will not bother users who don't need this.
This reuses lot of things from Alan contribution from #4484