The .ui files are all GPL-3.0-or-later style, but it's
slightly difficult to keep licensing information in them:
it's XML, so an XML comment might work, but there's no
guarantee that safe/load will preserve them.
Put the SPDX tags in the <author> tag, so that it's visible
in Qt Designer.
Package chooser is a **low density** package selector -- unlike
netinstall which offers a high density tree view -- for picking
zero, one, or more items from a small collection of packages.
This can be used, e.g., for "pick exactly one desktop environment",
"pick zero or more text editors" which can then be installed
by another module. The UI is big and shiny (rather than netinstall's
text-based tree view) and isn't suitable for more than a dozen or
so items.
