Refactoring: vaccination

src/flask_covid19/blueprints/app_all/all_model.py

src/flask_covid19/blueprints/data_ecdc/ecdc_model_import.py

...flask_covid19/blueprints/data_ecdc/ecdc_service_import.py

src/flask_covid19/blueprints/data_owid/owid_model_import.py

...flask_covid19/blueprints/data_owid/owid_service_import.py

src/flask_covid19/blueprints/data_rki/rki_model_import.py

src/flask_covid19/blueprints/data_rki/rki_service_import.py

...9/blueprints/data_vaccination/vaccination_model_import.py

...blueprints/data_vaccination/vaccination_service_import.py

...templates/who/fragments/fragment_who_flat_pagination.html

..._who/templates/who/fragments/fragment_who_flat_table.html

...k_covid19/blueprints/data_who/templates/who/who_flat.html

src/flask_covid19/blueprints/data_who/who_model_import.py

src/flask_covid19/blueprints/data_who/who_service_import.py