[SE-5313] Implement the footer component

Description

Contains the changes required to make the footer look like the new OpenCraft theme.

This footer is only shown on MFE pages. It has only been tested with the OpenCraft theme.

Supporting information

https://tasks.opencraft.com/browse/SE-5313 https://tasks.opencraft.com/browse/SE-5314

Testing instructions

• Enable the branding API by adding an enabled Branding API Config instance via the Django Admin.
• In the frontend-app-learning, Add to your module.config.js, assuming frontend-app-learning and frontend-component-footer live in the same directory.

    { moduleName: '@edx/frontend-component-footer', dir: '../frontend-component-footer', src: "src", dist: "../frontend-component-footer/dist" }

• Run npm run build in the frontend-component-footer folder.
• Restart the frontend-app-learning container.

Deadline

22 February 2022

Other information

• The footer has not been tested outside of the OpenCraft theme.
• The URLs shown in the footer are retrieved from the Branding API, which doesn't include the domain by default.
• Commits will be squashed after approval.