data: Generate dash/app-grid defaults from text files

Defining default apps as serialized GVariants isn't very human-friendly,
which likely contributes to the fact that the lists are in parts horribly
outdated (Books! Cheese! Screenshot! gedit!).

Instead, generate the lists at build time from simple text files, which
should be much easier to update.

Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/3632>

data/default-apps/app-grid.txt

@@ -0,0 +1,21 @@
+org.gnome.Geary.desktop
+org.gnome.Contacts.desktop
+org.gnome.Weather.desktop
+org.gnome.clocks.desktop
+org.gnome.Maps.desktop
+org.gnome.Books.desktop
+org.gnome.Photos.desktop
+org.gnome.Totem.desktop
+org.gnome.Calculator.desktop
+org.gnome.gedit.desktop
+simple-scan.desktop
+org.gnome.Settings.desktop
+org.gnome.SystemMonitor.desktop
+org.gnome.Boxes.desktop
+org.gnome.Terminal.desktop
+Utilities # folder
+org.gnome.Characters.desktop
+yelp.desktop
+org.gnome.Screenshot.desktop
+org.gnome.Cheese.desktop
+org.gnome.font-viewer.desktop

data/default-apps/dash.txt

@@ -0,0 +1,6 @@
+org.gnome.Epiphany.desktop
+org.gnome.Calendar.desktop
+org.gnome.Music.desktop
+gnome.Nautilus.desktop
+org.gnome.Software.desktop
+org.gnome.TextEditor.desktop

data/default-apps/utilities-folder.txt

@@ -0,0 +1,17 @@
+# Sorted by name as shown in menus, not filename
+nm-connection-editor.desktop              # Advanced Network Configuration
+org.gnome.DejaDup.desktop                 # Backups
+org.gnome.Characters.desktop              # Characters
+org.gnome.Connections.desktop             # Connections
+org.gnome.DiskUtility.desktop             # Disks
+org.gnome.baobab.desktop                  # Disk Usage Analyzer
+org.gnome.Evince.desktop                  # Document Viewer
+org.gnome.FileRoller.desktop              # File Roller
+org.gnome.font-viewer.desktop             # Fonts
+org.gnome.Loupe.desktop                   # Image Viewer
+org.gnome.Logs.desktop                    # Logs
+org.freedesktop.MalcontentControl.desktop # Parental Controls
+org.gnome.seahorse.Application.desktop    # Passwords and Keys
+org.freedesktop.GnomeAbrt.desktop         # Problem Reporting
+org.gnome.tweaks.desktop                  # Tweaks
+org.gnome.Usage.desktop                   # Usage

data/meson.build

@@ -100,6 +100,14 @@ install_data(keybinding_files, install_dir: keysdir)
 
 schemaconf = configuration_data()
 schemaconf.set('GETTEXT_PACKAGE', meson.project_name())
+schemaconf.set('DASH_APPS', run_command(
+  generate_app_list, 'default-apps/dash.txt',
+  check: true,
+).stdout())
+schemaconf.set('APP_GRID_APPS', run_command(
+  generate_app_list, '--pages', 'default-apps/app-grid.txt',
+  check: true,
+).stdout())
 schema = configure_file(
   input: 'org.gnome.shell.gschema.xml.in',
   output: 'org.gnome.shell.gschema.xml',

data/org.gnome.shell.gschema.xml.in

@@ -61,7 +61,9 @@
       </description>
     </key>
     <key name="favorite-apps" type="as">
-      <default>[ 'org.gnome.Epiphany.desktop', 'org.gnome.Calendar.desktop', 'org.gnome.Music.desktop', 'org.gnome.Nautilus.desktop', 'org.gnome.Software.desktop', 'org.gnome.TextEditor.desktop']</default>
+      <default>
+        @DASH_APPS@
+      </default>
       <summary>List of desktop file IDs for favorite applications</summary>
       <description>
         The applications corresponding to these identifiers
@@ -118,29 +120,7 @@
     </key>
     <key name="app-picker-layout" type="aa{sv}">
       <default><![CDATA[
-        [{
-          'org.gnome.Geary.desktop': <{'position': <0>}>,
-          'org.gnome.Contacts.desktop': <{'position': <1>}>,
-          'org.gnome.Weather.desktop': <{'position': <2>}>,
-          'org.gnome.clocks.desktop': <{'position': <3>}>,
-          'org.gnome.Maps.desktop': <{'position': <4>}>,
-          'org.gnome.Books.desktop': <{'position': <5>}>,
-          'org.gnome.Photos.desktop': <{'position': <6>}>,
-          'org.gnome.Totem.desktop': <{'position': <7>}>,
-          'org.gnome.Calculator.desktop': <{'position': <8>}>,
-          'org.gnome.gedit.desktop': <{'position': <9>}>,
-          'simple-scan.desktop': <{'position': <10>}>,
-          'org.gnome.Settings.desktop': <{'position': <11>}>,
-          'org.gnome.SystemMonitor.desktop': <{'position': <12>}>,
-          'org.gnome.Boxes.desktop': <{'position': <13>}>,
-          'org.gnome.Terminal.desktop': <{'position': <14>}>,
-          'Utilities': <{'position': <15>}>,
-          'org.gnome.Characters.desktop': <{'position': <16>}>,
-          'yelp.desktop': <{'position': <17>}>,
-          'org.gnome.Screenshot.desktop': <{'position': <18>}>,
-          'org.gnome.Cheese.desktop': <{'position': <19>}>,
-          'org.gnome.font-viewer.desktop': <{'position': <20>}>
-        }]
+        @APP_GRID_APPS@
       ]]></default>
       <summary>Layout of the app picker</summary>
       <description>