### Description of Changes
ran yapf for the branch
[TESTING->locally using docker compose]
Issue: https://coreosdev.atlassian.net/browse/QUAY-632
## Reviewer Checklist
- [ ] It works!
- [ ] Comments provide sufficient explanations for the next contributor
- [ ] Tests cover changes and corner cases
- [ ] Follows Quay syntax patterns and format
this decouples the database models from the api
[TESTING->locally with docker compose]
Issue: https://coreosdev.atlassian.net/browse/QUAY-632
- [ ] It works!
- [ ] Comments provide sufficient explanations for the next contributor
- [ ] Tests cover changes and corner cases
- [ ] Follows Quay syntax patterns and format
this adds tests for the pro oci model
Issue: https://coreosdev.atlassian.net/browse/QUAY-632
- [ ] It works!
- [ ] Comments provide sufficient explanations for the next contributor
- [ ] Tests cover changes and corner cases
- [ ] Follows Quay syntax patterns and format
### Description of Changes
Issue: https://coreosdev.atlassian.net/browse/QUAY-632
## Reviewer Checklist
- [ ] It works!
- [ ] Comments provide sufficient explanations for the next contributor
- [ ] Tests cover changes and corner cases
- [ ] Follows Quay syntax patterns and format
this creates an interface for hidding details of the data model for pre oci and post oci code
Issue: https://coreosdev.atlassian.net/browse/QUAY-632
- [ ] It works!
- [ ] Comments provide sufficient explanations for the next contributor
- [ ] Tests cover changes and corner cases
- [ ] Follows Quay syntax patterns and format
Makes the lookup query underneath the transaction smaller if there are a lot of images referenced directly by tag. We still must do the direct referenced check within the transaction, but this should reduce the scope of the search space a bit.
This prevents us from creating a massive join when there are a large number of tags in the repository, which can result in locking the entire DB for long periods of time. Instead of the join, we just iteratively lookup any images found to be directly referenced by a tag or found as a parent of another image, both of which should be indexed lookups. Once done, we only remove those images and then iterate until the working set stops changing.
