User story: As a content creator, I want to be able to set a short background video on a section of content, so that I make make my content more visually engaging to the end user.

Context: 

Wordpress 5.5 introduced the 'Group' block, a simple container block that allows users to create a 'group' and add other blocks inside it. It then allows the user to customize the group further by setting a background color, text color, and extra css classes and 'anchor' (id).

I think it makes sense to enable this block once we upgrade to 5.5, and build on it to allow users to set a video background.

 Instead of hacking on the group block to make it do what we need, we're now investigating the 'covers' block: https://wordpress.org/support/article/cover-block/

Questions

• Should this field be upload, link to external url, or have both options?
• Should we limit video length, size, etc?
• should we add an option for an overlay and the ability to set an opacity? (to replace happy point)
• mfatome do you think it makes sense to allow a photo background as well?

Tasks:

1. Make POC
2. enable group block (will be done at PLANET-5499)
3. add additional field for video
4. add field for fallback photo (or background color) for mobile. (Investigate if we can also use connectivity js API for detection)
5. add validation to ensure that video meets Magali's criteria

1. enable covers block
2. check functionality against Magali's criteria
3. add link to documentation with recommendations, as a help text
4. investigate if we can run a11y tests in the block (eg. if there is already a js library that does that) and open a follow up ticket