gnome-shell depends on network-manager-applet
I investigated where the "Advanced Network Configuration" icon comes from, which recently showed up in Phosh. It's from network-manager-applet, this patch specifically.
network-manager-applet contains nm-connection-editor. phosh depends on gnome-session, which depends on network-manager-applet.
@Cogitri: why does gnome-shell depend on network-manager-applet? It looks to me that this should not be required (anymore). The logic that gnome-control-center needs from network-manager-applet has apparently been split to libnma, as the linked patch explains.