Takedown form

Fixes https://gitlab.softwareheritage.org/product-management/swh-archive-website/-/work_items/7

Requests for takedowns are currently made by email, and sometimes require multiple round trips to gather all the information required for the request.

The goal of this MR is to set up a simple form on archive.softwareheritage.org to collect all these information in a single step.

As the process for handling requests is still a WIP, the form will simply transmit all the data by e-mail to the address currently in use for takedowns.

Checklist

• a dedicated takedown app
• a /requests/takedown/ route + view
• a form inspired by https://design.penpot.app/#/view/5043754c-325d-80e8-8003-15b8e20f9502
• validate origins
• explanatory text (copied from swh.org's content policy)
• confirmation messages
• send the request takedown@swh
• send a confirmation to contact_email
• send mail settings / yml
• check a11y
• gpdr compliance ?
• smtp config for production ?

Workflow

flowchart TD
    A("/requests/takedown") --> B["Fill form"]
    B --> |POST| C{Form validation}
    C -->|Invalid| B
    C -->|Valid| E[Send takedown request and confirmation emails]
    E --> |redirect + success message| A

Screenshots

individual	entity	confirmation	error