Refactoring: rename covid19 to flask_covid19ssaas

src/flask_covid19/blueprints/data_vaccination/__init__.py

...id19/blueprints/data_vaccination/rki_vaccination_model.py

...ueprints/data_vaccination/rki_vaccination_model_import.py

...19/blueprints/data_vaccination/rki_vaccination_service.py

...prints/data_vaccination/rki_vaccination_service_import.py

...prints/data_vaccination/rki_vaccination_service_update.py

...id19/blueprints/data_vaccination/rki_vaccination_views.py

...covid19/blueprints/data_vaccination/templates/__init__.py

.../templates/rki_vaccination/data/rki_vaccination_data.html

...rki_vaccination/data/rki_vaccination_data_pagination.html

...ates/rki_vaccination/data/rki_vaccination_data_table.html

...rki_vaccination/data/rki_vaccination_data_table_head.html

...es/rki_vaccination/imported/rki_vaccination_imported.html

...ination/imported/rki_vaccination_imported_pagination.html

..._vaccination/imported/rki_vaccination_imported_table.html

...ccination/navigation/rki_vaccination_navbar_dropdown.html

...s/rki_vaccination/navigation/rki_vaccination_navtabs.html

...ation/templates/rki_vaccination/rki_vaccination_info.html

...tion/templates/rki_vaccination/rki_vaccination_tasks.html