Context rework

What is in this MR

This MR introduces a light rework of the context component. Design wise everything has stayed the same. I've just added a generic context__footer class to avoid CSS code repetition.

I've added the component in Storybook and some unit tests. I've also changed how the boolean attributes were written for better code readability.

How to test this MR

• Run yarn run storybook in the frontend container, open http://localhost:6006 in your browser and check the behaviors of the Context Menu stories.
• In the app, check if the Filters, Sort, and Group By contexts footers display nicely and work as expected.

Merge Request Checklist

• changelog.md hasbeen updated if required.
• New/updated Premium/Enterprise features are separated correctly in the premium or enterprise folder
• The latest Chrome and Firefox have been used to test any new frontend features
• Documentation has been updated
• Quality Standards are met
• Performance: tables are still fast with 100k+ rows, 100+ field tables
• The redoc API pages have been updated for any REST API changes
• Our custom API docs are updated for changes to endpoints accessed via api tokens
• The UI/UX has been updated following UI Style Guide