Previously the V2 Wizard's request mapper was only adding the
custom_repositories field. We also need to add a nearly duplicate
payload_repositories field due to how the image-builder API works...
which is admittedly not intuitive.
Tests are also added to ensure that requests are generated correctly
when using the custom repositories feature.
This creates a new folder for the Repositories step and copies over all needed files:
- Repositories.tsx
- RepositoriesStatus.tsx
- RepositoryUnavailable.tsx
