chore: ignore lib/firebase_options.dart

chore: upgrade dependencies

chore: regenerated splash images

chore: update dependencies

feat: upgrade dependencies

chore: implement Dio (and DioMixin) for HttClient instead of having Dio as property

chore: run formatting

chore: platform improvements

fix: resolve type errors

feat: update documentation

feat: retain native spalsh screen until Flutter app is ready

feat: move .env-sample file to the project root as is convention

feat: get to the newest versions of packages

chore: fixed new static analysis issues

feat: get on the latest version of Dart