xfce.xfce4-appfinder: Move away from mkXfceDerivation

To reduce the diff when build system change comes.
mkXfceDerivation is generally pointless with meson.

pkgs/desktops/xfce/core/xfce4-appfinder/default.nix

@@ -1,22 +1,38 @@
 {
+  stdenv,
   lib,
-  mkXfceDerivation,
-  exo,
+  fetchFromGitLab,
+  gettext,
+  pkg-config,
+  xfce4-dev-tools,
+  wrapGAppsHook3,
   garcon,
   gtk3,
   libxfce4util,
   libxfce4ui,
   xfconf,
+  gitUpdater,
 }:
 
-mkXfceDerivation {
-  category = "xfce";
+stdenv.mkDerivation (finalAttrs: {
   pname = "xfce4-appfinder";
   version = "4.20.0";
 
-  sha256 = "sha256-HovQnkfv5BOsRPowgMkMEWQmESkivVK0Xb7I15ZaOMc=";
+  src = fetchFromGitLab {
+    domain = "gitlab.xfce.org";
+    owner = "xfce";
+    repo = "xfce4-appfinder";
+    tag = "xfce4-appfinder-${finalAttrs.version}";
+    hash = "sha256-HovQnkfv5BOsRPowgMkMEWQmESkivVK0Xb7I15ZaOMc=";
+  };
+
+  nativeBuildInputs = [
+    gettext
+    pkg-config
+    xfce4-dev-tools
+    wrapGAppsHook3
+  ];
 
-  nativeBuildInputs = [ exo ];
   buildInputs = [
     garcon
     gtk3
@@ -25,8 +41,20 @@ mkXfceDerivation {
     xfconf
   ];
 
+  configureFlags = [ "--enable-maintainer-mode" ];
+  enableParallelBuilding = true;
+
+  passthru.updateScript = gitUpdater {
+    rev-prefix = "xfce4-appfinder-";
+    odd-unstable = true;
+  };
+
   meta = {
     description = "Appfinder for the Xfce4 Desktop Environment";
+    homepage = "https://gitlab.xfce.org/xfce/xfce4-appfinder";
+    license = lib.licenses.gpl2Plus;
+    mainProgram = "xfce4-appfinder";
+    platforms = lib.platforms.linux;
     teams = [ lib.teams.xfce ];
   };
-}
+})