Reduce duplication in the view queryset code

[spopelka-dsac]

module-name: Reduce duplication in the view queryset code

Jira Ticket

Problem

We had our view querysets defined independently for our list() and retrieve() view methods, which made it harder to maintain the code, ensure consistency, and identify room for improvement from a performance standpoint.

Solution

This PR pulls all the queryset logic into a class attribute that is referenced by the list() and retrieve() methods, so the code for each view only needs to be maintained in one place. For clarity and consistency, this PR also moves the order by logic to the ordering class attribute.

These changes make it easier to understand and maintain the code, which in turn makes it easier to perform performance improvements and future code updates.

Test Plan

All tests should pass