Internationalization (German) of the mobile app. (#246)

* Add i18n framework to mobile app and write simple translation generator

* Replace all texts in login_form with i18n keys

* Localization of sharing section

* Localization of asset viewer section

* Use JSON as base translation format

* Add check for missing/unused translation keys

* Add localizely

* Remove i18n directory in favour of localizely

* Backup Translation

* More translations

* Translate home page

* Translation of search page

* Translate new server version announcement

* Reformat code

* Fix typo in german translation

* Update englisch translations

* Change translation keys to match dart filenames

* Add /api to translated endpoint_urls

* Update localizely.yml

* Add languages to ios plist

* Remove unused keys

* Added script to check outdated key in other translations

* Add download key to localizely.yml

Co-authored-by: Alex <alex.tran1502@gmail.com>

mobile/lib/modules/search/ui/thumbnail_with_info.dart

@@ -55,7 +55,7 @@ class ThumbnailWithInfo extends StatelessWidget {
                 child: SizedBox(
                   width: MediaQuery.of(context).size.width / 3,
                   child: Text(
-                    textInfo.capitalizeFirstLetter(),
+                    textInfo,
                     style: const TextStyle(
                       color: Colors.white,
                       fontWeight: FontWeight.bold,