FEAT: add open data page

config/routes.php

src/Controller/Api/V1/PagesController.php

src/Locale/Breadcrumbs.pot

src/Locale/ElementNavigation.pot

src/Locale/Pages.pot

src/Locale/en/Breadcrumbs.po

src/Locale/en/ElementNavigation.po

src/Locale/en/Pages.po

src/Locale/fr/Breadcrumbs.po

src/Locale/fr/ElementNavigation.po

src/Locale/fr/Pages.po

src/Template/Api/V1/Pages/opendata.ctp

src/Template/Element/Pages/footer.ctp

tests/Acceptance/BasicTestsCest.php

tests/Acceptance/CheckBreadcrumbCest.php