Gnome Shell 47 compatibility, build system updates

• Gnome Shell 47 compatibility.
• Update meson-gse:
  • Now requires meson 1.4.0 or later.
  • Build now runs eslint on test, added prettier target.
• Update to pass eslint.
• Code reformatted with prettier.

Translations update

• Update Dutch translation by Heimen Stoffels (@Vistaus).
• Minor punctuation fixes in other translations.

Bugfix release

• Fix race condition at shell start-up.

Major update: any application can be added to the system menu.

• Now supports adding any application to the system menu.
• Defaults to adding Gnome Tweaks, Extensions, and Extension Manager.
• The preferences dialog has been reimplemented with the Adwaita toolkit.
• Settings from previous versions will be lost upon upgrade.

Gnome Shell 45 & 46 compatibility

• Gnome Shell 45 & 46 compatibility.
• Add translation for:
  • Czech (courtesy of @Amereyeu).
• Now incompatible with all older Gnome Shell lower than 45.
  - Gnome Shell 43 and 44 are not supported.
  - Version 18 works for Gnome Shell 3.36 through 42.
  - Version 8 works for Gnome Shell 3.28 through 3.34.

Gnome-shell 42 compatibility

• Gnome Shell 42 compatibility.
• Update instructions to use gnome-extensions instead of manually unzipping.

v17: Release version 17.

• Declare compatibility with version 40 and 41 of Gnome Shell instead of using minor versions (40.0 and 41.1). This should clear reports of the extension being incompatible with well-supported versions.
• Update Japanese translation (thanks to @yukkeorg).
• Update meson-gse:
  • Fix build issues with meson 0.60.0.
  • Bump minimum meson version to 0.50.0.
• Clean up code:
  • Remove Lang imports.
  • Use ExtensionUtils for getSettings/initTranslations instead of using meson-gse's convenience.js.

Gnome-shell 41 compatibility, new translations & bugfixes.

• Gnome-shell 41 compatibility.
• Add translations for:
  • Dutch (courtesy of @Vistaus).
  • Japanese (courtesy of @yukkeorg).
  • Korean (courtesy of @kuroehanako).
  • Spanish (courtesy of @fjsevilla-dev).
• Improve Gnome Extensions detection (courtesy of @stefangweichinger).

Update German translation.

• Update and generalize German translation.

Support for Extensions button in System Menu for Gnome 40.

• Support showing both Tweaks and Extensions (Extensions only on Gnome 40 and later).
• Update meson-gse to latest:
  • Fix logging bug in preferences.