Refactoring: vaccination

src/flask_covid19/blueprints/data_ecdc/ecdc_views.py

...9/blueprints/data_ecdc/templates/ecdc/flat/ecdc_flat.html

...s/data_ecdc/templates/ecdc/flat/ecdc_flat_pagination.html

...prints/data_ecdc/templates/ecdc/flat/ecdc_flat_table.html

...s/data_ecdc/templates/ecdc/flat/ecdc_flat_table_head.html

...cdc/templates/ecdc/imported/ecdc_imported_pagination.html

...ata_ecdc/templates/ecdc/imported/ecdc_imported_table.html

...cdc/templates/ecdc/imported/ecdc_imported_table_head.html

..._ecdc/templates/ecdc/navigation/ecdc_navbar_dropdown.html

...nts/data_ecdc/templates/ecdc/navigation/ecdc_navtabs.html