netstatus could use updated icon names

[newhoa]

Issue reported to debian bug tracker here.

The netstatus plugin still uses the old gnome-netstatus-* icon names. These icon names have been depricated for a very long time, and the names from the [FreeDesktop.org Icon Naming Specification] (https://specifications.freedesktop.org/icon-naming-spec/icon-naming-spec-latest.html) would be better to use. Most icon themes will have the FD.o names and not the gnome- prefixed names.

FD.o names include:

network-wired
network-wireless
network-error
network-idle
network-offline
network-receive
network-transmit
network-transmit-receive

Not part of FD.o but widely used (are in KDE's Breeze and Gnome's Adwaita icon themes):

network-wireless-signal-none
network-wireless-signal-weak
network-wireless-signal-ok
network-wireless-signal-good
network-wireless-signal-excellent

A quick grep shows where the names are used. It may be as simple as switching the icon names.

$ grep -r --exclude=\*.{po, Po, plo, Plo, gmo, svg, pot, intltool-merge-cache} gnome-netstatus-
data/Makefile.am:	images/gnome-netstatus-0-24.png \
data/Makefile.am:	images/gnome-netstatus-25-49.png \
data/Makefile.am:	images/gnome-netstatus-50-74.png \
data/Makefile.am:	images/gnome-netstatus-75-100.png \
data/Makefile.am:	images/gnome-netstatus-disconn.png \
data/Makefile.am:	images/gnome-netstatus-error.png \
data/Makefile.am:	images/gnome-netstatus-idle.png \
data/Makefile.am:	images/gnome-netstatus-rx.png \
data/Makefile.am:	images/gnome-netstatus-txrx.png \
data/Makefile.am:	images/gnome-netstatus-tx.png \
plugins/netstatus/netstatus-dialog.c:	// gnome_help_display_on_screen ("gnome-netstatus", "gnome-netstatus-props", screen, &error);
plugins/netstatus/netstatus-dialog.c:  if ((icon_info = gtk_icon_theme_lookup_icon (icon_theme, "gnome-netstatus-tx", 48, 0)))
plugins/netstatus/netstatus-icon.c:			      "gnome-netstatus-disconn");
plugins/netstatus/netstatus-icon.c:			      "gnome-netstatus-idle");
plugins/netstatus/netstatus-icon.c:			      "gnome-netstatus-tx");
plugins/netstatus/netstatus-icon.c:			      "gnome-netstatus-rx");
plugins/netstatus/netstatus-icon.c:			      "gnome-netstatus-txrx");
plugins/netstatus/netstatus-icon.c:			      "gnome-netstatus-error");
plugins/netstatus/netstatus-icon.c:			      "gnome-netstatus-0-24");
plugins/netstatus/netstatus-icon.c:			      "gnome-netstatus-25-49");
plugins/netstatus/netstatus-icon.c:			      "gnome-netstatus-50-74");
plugins/netstatus/netstatus-icon.c:			      "gnome-netstatus-75-100");