[Testing]: Setup django-test-migrations

[jackton1]

Explore using https://pypi.org/project/django-test-migrations/ to verify migration nodes output.

• Test more than 1 migration conflict on a PR branch
• Test re-seeding migrations based on a parent branch i.e can this be aware of main <- branch a <- branch b, Updates branch a using main but branch b based on branch a (Can be solved using github actions.)
• Test using a different default branch.
• Test all of the above using (named and numbered migrations).