Story

As a user of RHDH, I want to have a plugin marketplace. For this we need a backend and frontend plugin that communicates together.

Acceptance Criteria

1. New marketplace-backend plugin
2. New marketplace-frontend plugin
3. New marketplace-common plugin
4. Show the new Marketplace page as a tab on the administration page via the dynamic plugin extension.
5. Add a feature flag to show the marketplace only if the feature flag is enabled
6. Specifiy a simple Plugin type in marketplace-common and return some mock data in marketplace-backend
7. Fetch and show the data on the plugin page (mostly unstyled is fine because we will have a follow-up story to create a list view with e2e tests)
8. Update the dev page to show some mock data there as well without the backend (unstyled again)

For the initial plugin type definition see Figma Design > see Administration Plugins / Plugins catalog

Could the API follow the "Kubernetes like" Catalog API design with annotations and labels?

Implementation note

1. Plugins can be created in backstage-plugins or backstage-showcase
2. We can consider extracting some code into https://github.com/redhat-developer/aonic-ui