gnomeExtensions: add 'uuid' attr to all extensions

Some already have it, this adds it to the rest.

With all extensions having an 'uuid' attr we can do cool things like
declaratively enable extensions on NixOS.

pkgs/desktops/gnome-3/extensions/arc-menu/default.nix

@@ -24,6 +24,8 @@ stdenv.mkDerivation rec {
 
   makeFlags = [ "INSTALLBASE=${placeholder "out"}/share/gnome-shell/extensions" ];
 
+  uuid = "arc-menu@linxgem33.com";
+
   meta = with stdenv.lib; {
     description = "Gnome shell extension designed to replace the standard menu found in Gnome 3";
     license = licenses.gpl2Plus;

pkgs/desktops/gnome-3/extensions/dash-to-dock/default.nix

@@ -25,6 +25,8 @@ stdenv.mkDerivation rec {
     "INSTALLBASE=${placeholder "out"}/share/gnome-shell/extensions"
   ];
 
+  uuid = "dash-to-dock@micxgx.gmail.com";
+
   meta = with stdenv.lib; {
     description = "A dock for the Gnome Shell";
     homepage = "https://micheleg.github.io/dash-to-dock/";

pkgs/desktops/gnome-3/extensions/dash-to-panel/default.nix

@@ -17,6 +17,8 @@ stdenv.mkDerivation rec {
 
   makeFlags = [ "INSTALLBASE=$(out)/share/gnome-shell/extensions" ];
 
+  uuid = "dash-to-panel@jderose9.github.com";
+
   meta = with stdenv.lib; {
     description = "An icon taskbar for Gnome Shell";
     license = licenses.gpl2;

pkgs/desktops/gnome-3/extensions/gsconnect/default.nix

@@ -73,6 +73,8 @@ stdenv.mkDerivation rec {
     done
   '';
 
+  uuid = "gsconnect@andyholmes.github.io";
+
   meta = with stdenv.lib; {
     description = "KDE Connect implementation for Gnome Shell";
     homepage = "https://github.com/andyholmes/gnome-shell-extension-gsconnect/wiki";

pkgs/desktops/gnome-3/extensions/no-title-bar/default.nix

@@ -25,6 +25,8 @@ stdenv.mkDerivation rec {
 
   makeFlags = [ "INSTALLBASE=$(out)/share/gnome-shell/extensions" ];
 
+  uuid = "no-title-bar@franglais125.gmail.com";
+
   meta = with stdenv.lib; {
     description = "Integrates maximized windows with the top panel";
     homepage = "https://github.com/franglais125/no-title-bar";

pkgs/desktops/gnome-3/extensions/pidgin-im-integration/default.nix

@@ -21,6 +21,8 @@ stdenv.mkDerivation rec {
     mv *.js metadata.json dbus.xml schemas locale "$extensions_dir"
   '';
 
+  uuid = "pidgin@muffinmad";
+
   meta = with stdenv.lib; {
     homepage = "https://github.com/muffinmad/pidgin-im-gnome-shell-extension";
     description = "Make Pidgin IM conversations appear in the Gnome Shell message tray";

pkgs/desktops/gnome-3/extensions/topicons-plus/default.nix

@@ -17,6 +17,8 @@ stdenv.mkDerivation rec {
 
   makeFlags = [ "INSTALL_PATH=$(out)/share/gnome-shell/extensions" ];
 
+  uuid = "TopIcons@phocean.net";
+
   meta = with stdenv.lib; {
     description = "Brings all icons back to the top panel, so that it's easier to keep track of apps running in the backround";
     license = licenses.gpl2;