Refactoring: rename covid19 to flask_covid19

src/flask_covid19/blueprints/app_admin/app_admin_views.py

src/flask_covid19/blueprints/app_all/all_views.py

src/flask_covid19/blueprints/app_user/user_service.py

src/flask_covid19/blueprints/app_user/user_views.py

src/flask_covid19/blueprints/divi/divi_service.py

src/flask_covid19/blueprints/divi/divi_service_import.py

src/flask_covid19/blueprints/divi/divi_service_update.py

src/flask_covid19/blueprints/divi/divi_views.py

src/flask_covid19/blueprints/divi_test/divi_test_service.py

src/flask_covid19/blueprints/divi_test/divi_test_views.py

src/flask_covid19/blueprints/ecdc/ecdc_service.py

src/flask_covid19/blueprints/ecdc/ecdc_service_import.py

src/flask_covid19/blueprints/ecdc/ecdc_service_update.py

src/flask_covid19/blueprints/ecdc/ecdc_views.py

src/flask_covid19/blueprints/ecdc_test/ecdc_test_service.py

src/flask_covid19/blueprints/ecdc_test/ecdc_test_views.py

src/flask_covid19/blueprints/owid/owid_service.py

src/flask_covid19/blueprints/owid/owid_service_import.py

src/flask_covid19/blueprints/owid/owid_service_update.py

src/flask_covid19/blueprints/owid/owid_views.py