Provide lightweight video view for Letterbox

[defagos]

As an SRF developer I need a simple way to display a video in a news feed, without any loading placeholder, controls or buttons.

Acceptance criteria

• A basic video view is available for Letterbox.

Tasks

• [ ] Implement lightweight video view for Letterbox.
• [ ] Update documentation.

[defagos]

Implemented in Letterbox successor Pillarbox. Will not be implemented. Closed.