Replace static fixtures with factory-generated fixtures

[grahamalama]

This issue will track the work of migrating test objects from interdependent pytest fixtures and static data to factory generated fixtures.

Acceptance criteria:

• Most test data should be generated by a factory
• In tests that simply on the default invocation of a factory, a named instance of a factory can be used. It should preferably be defined at the module or some_package.conftest level, but if needed, the top-level conftest.py