feat: new catalog query read only viewset

[alex-sheehan-edx]

Part 1 of https://2u-internal.atlassian.net/browse/ENT-8661

Platform/enterprise needs a way of checking if a particular query/content filter already exists in the catalog service. To do this, I've created a readonly viewset with an endpoint that can fetch queries by hashes.

Post-review

• [ ] Squash commits into discrete sets of changes
• [ ] Ensure that once the changes have been deployed to stage, prod is manually deployed