Short net names are not unique; full names with paths must be used.
Added a grid cell renderer that does the escaping, to make it easier
to display net names in grid cells.
Once you unescape a net name, you can't go back to the escaped form
because you can't assume which `/` should be {slash} and which `/`
Because of this, we cannot use Unescape/Escape on the data model in
the netclass setup panel, and instead do the Unescape in the view.
Fixes https://gitlab.com/kicad/code/kicad/-/issues/5331
The old way of checking for focus loss caused GTK to be unable to
even open the combobox. This way checks for the event sent when the
list closes and uses that to close the grid editor.
Fixes https://gitlab.com/kicad/code/kicad/issues/4617
ADDED Eeschema-specific netclass settings including wire and bus
thickness, color, and line style.
Netclasses override individual wire & bus colors and line styles.
If that proves an issue we might look at something more sophisticated
with inheritance.
Fixes https://gitlab.com/kicad/code/kicad/issues/4581