Polish tests to use the template data

Right now, the tests adds a bunch of sources (with fruit names) and made up publications.

Some of these are needed to test the ingest functions, but we should use the template data for as many tests as possible. Or, at least add the data in conftest.py rather than in the tests.

Also, consider removing the fruity/made up data so the template database will stay the same even after the tests run.

Review the tests that add fruit-named sources and made-up publications, then inspect conftest.py and the template data they can reuse. Run the relevant test suite to identify which fixtures are required for ingest coverage; done means unnecessary test data is centralized or removed without changing the template database after tests run.

Written by the indexing model from the issue text.