Gateway | Replace onboarding flow with new account review and newsletters pages

[raphaelkabo]

This PR removes the consents framework (a kind of onboarding flow) to simplify post-registration behaviour. It's part of a wider redesign project to improve the mandatory registration experience for our users - this is the part of the redesign where we change the flow sequence, rather than the visual frontend designs.

New flow

• New users, after verifying their social login/setting their password, will now go to the page /welcome/review, which allows them to select their consents for personalized advertising and marketing.
• The submit button on that page will take them to the URL from which they originated (a newspaper article, for instance).
• The exception is if the user is currently geolocated in Australia or the US. In this case, they will be taken to a page where they can subscribe to a small set of newsletters. Clicking submit on that page will take them to the originating URL.

The geolocation-based behaviour is a MVP test of a 'next best action' framework for user registrations. In future, we may select a next best action for the user after they confirm consents, based on geolocation, login type, login app, and other factors.

Changes

• Remove the consents framework and its support files, tests, etc.
• Create a new page, /welcome/review, which is shown after password set (for email registrations) or social registration confirmed (for social registrations). This page displays consent toggles for personalized advertising and marketing, along with supporting text.
• Create a new page, /welcome/newsletters, which is shown for some users (see flow section above). This displays new-style checkboxes for a set of geolocation-appropriate newsletters, along with supporting text.
• Change some wording on the password set page.
• Update tests which used /consents/* as a final return URL page to use /welcome/review instead.
• Add a new ETE test suite for the new account review page and the newsletters page.
• Add Storybook stories for the new account review page and newsletters page.
• Add a flag in the change password handler for when the password is being changed as part of a new account registration, and make use of this flag in the OAuth callback route to send the user correctly to the new account review page when they're registering via an app.

New designs

Set password page	Password set page	New account review page

Newsletters page designs

US	AU	Some selected	Error fetching newsletters

Tests

As well as our new Cypress tests, we're using this manual testing matrix to ensure everything behaves the way we expect:

• Tested in CODE
• Tested in PROD

Related PRs

• Gateway | New designs #2670

[coldlink]

I think this is looking amazing now! Really brilliant work. 🌵

[coldlink]

All green 🌲