[Enhancement] Importer Badges

Knowing when our importers are failing when they do would help us and downstream in future.
There are multiple ways I'm thinking to add this feature

1. The action at https://github.com/nexB/vulnerablecode/blob/87ffa8109e4f5dcb22b4c8d71eaf1711c82068d7/.github/workflows/upstream_test.yml is perfect in itself. We can just add a badge for the workflow and be done with that. Whenever any importer fails, we look at the logs and figure out how to proceed.
2. We change or create a similar action to one above with some changes
- The action as a whole never fails
- After running all the tests, it generates svgs for passing and failing importers and merges them in to one single svg
- The final svg is displayed at the project home
- This way we'll know exactly which importer is failing/passing directly looking at the home
3. Other suggestions ?