#8005670 Add-ons: Create Storage Add On Card Item

Fixes 1722-gh-Automattic/martech

Proposed Changes

Create the card item for the storage add on

Testing Instructions

1. Checkout this branch
2. Run yarn & yarn start
3. Go to http://calypso.localhost:3000/add-ons/YOUR_SITE_SLUG
4. You should see 2 new cards items – a 50 GB and a 100 GB storage add ons:

5. Click on the Buy add-on button. You should get redirected to the cart with the correct storage amount applied: