Update AppImage build configuration

This update removes various icon-theme exclusions from the AppImage build configuration and includes specific hicolor
icon files. It also adds new environment variables and path mappings for handling user data more efficiently within the
AppImage. This aims to optimize the packing process and improve the resultant AppImage's compatibility and performance.

Contributes to CURA-11132

packaging/AppImage-builder/AppImageBuilder.yml.jinja

@@ -48,12 +48,10 @@ AppDir:
         main
     include:
       - xdg-desktop-portal-kde:amd64
-    exclude:
-      - hicolor-icon-theme
-      - adwaita-icon-theme
-      - humanity-icon-theme
+    exclude: []
   files:
-    include: []
+    include:
+      - usr/share/icons/hicolor/*
     exclude:
     - usr/share/man
     - usr/share/doc/*/README.*
@@ -67,6 +65,9 @@ AppDir:
       QT_PLUGIN_PATH: "$APPDIR/qt/plugins"
       QML2_IMPORT_PATH: "$APPDIR/qt/qml"
       QT_QPA_PLATFORMTHEME: xdgdesktopportal
+      XDG_DATA_HOME: "$APPDIR/usr/share"
+    path_mappings:
+      - /usr/share:$APPDIR/usr/share
   test:
     fedora-30:
       image: appimagecrafters/tests-env:fedora-30