### Description of Changes
Issue: https://coreosdev.atlassian.net/browse/QUAY-633
## 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 is a part of getting ready for oci stuff
[TESTING->using new PR stack]
Issue: https://coreosdev.atlassian.net/browse/QUAY-633
- [ ] It works!
- [ ] Comments provide sufficient explanations for the next contributor
- [ ] Tests cover changes and corner cases
- [ ] Follows Quay syntax patterns and format
* Add flag to enable trust per repo
* Add api for enabling/disabling trust
* Add new LogEntryKind for changing repo trust settings
Also add tests for repo trust api
* Add `set_trust` method to repository
* Expose new logkind to UI
* Fix registry tests
* Rebase migrations and regen test.db
* Raise downstreamissue if trust metadata can't be removed
* Refactor change_repo_trust
* Add show_if to change_repo_trust endpoint