Udata-gouvfr

- Read Only Mode modifications on theme [509](https://github.com/etalab/udata-gouvfr/pull/509):
- Will display a warning banner on the frontend view.
- Hides the contribute's home's modal.
- Hides the Reuse's creation card and community resource's creation card on dataset view.
- Newsletter's subscription banner [512](https://github.com/etalab/udata-gouvfr/pull/512):
- Override alert section in posts list template to display newsletter's subscription banner.
- Add settings `POST_BANNER_ACTIVATED` to toggle banner's activation.
- Add settings `POST_BANNER_LINK` and `POST_BANNER_MESSAGE` to configure subscription's link and message.

- Add news link to posts list [504](https://github.com/etalab/udata-gouvfr/pull/504)

- Pinned udata version to fix transitive requests dependencies [500](https://github.com/etalab/udata-gouvfr/pull/500)

- Banner is now generic and configurable [499](https://github.com/etalab/udata-gouvfr/pull/499)
- Fix links in static pages

- Show api.gouv.fr APIs on dataset page [493](https://github.com/etalab/udata-gouvfr/pull/493)

- Mise à jour de l'URL de Geo SIRENE [489](https://github.com/etalab/udata-gouvfr/pull/489)
- Add footer link to pages summary and page cache [488](https://github.com/etalab/udata-gouvfr/pull/488)