Boy this was hard.
To ease the pain of porting wireless-security to GTK4, add
a new WsFileChooserButton class that mimics the behavior of
a button that triggers a filechooser, as per the migration
guide suggests.
There were lots of GtkGrids, so the diff is particularly
horrendous. Sorry.
This needs serious testing before landing.
We also remove support for WiMAX (now unsupported by NetworkManager),
and InfiniBand (Enterprise feature), and the use of
the deprecated NM_SETTING_WIRELESS_SEC property.
With help from network-manager-applet patches by Jiří Klimeš and
Dan Winship.
https://bugzilla.gnome.org/show_bug.cgi?id=765910
This code is fairly independent of the rest, and we don't want
net-device-wifi.c to become too massive and unmaintainable.
The code in connection-editor/ is fairly similar to
nm-connection-editor, with some simplification because we
currently only edit wireless connections.
The code in wireless-security/ is almost a straight copy
of the same code in nm-connection-editor, with some changes
to the .ui files to make them fit better in the new design.
