🎨 Ignore ManyToOneRel in get_relational_fields

[falexwolf]

User is a foreign key on almost all entities. For any given user, I might find it convenient to query all artifacts that the user ingested via: user.artifact_set.all()

However, I have a hard time imagining a query that looks like so because the result is always going to be exactly one user; the user that’s directly available as artifact.created_by

ln.User.filter(artifact=artifact).all()

Sometimes, I might only have the uid of an artifact. In that case, I can either query the user table or the artifact table directly. Querying the user table will be slightly faster.

ln.User.get(artifact__uid=artifact_uid)

The clutter produced by accounting for these backward references is enormous. For instance, on User:

I conclude that the minimal benefits in convenience for writing queries of the form user.artifact_set.all() do not justify the clutter in the API.

This present PR is making a change that hides these backward relationships (ManyToOneRel).

A second PR will create a migration that prevents Django from dynamically generating these attributes.

Internal reference.