[FEATURE] Switch Node-Media direction

[rosiel]

Overview of feature request

Switch the node-media direction.

This would give us much simpler formatting for display. Right now, the chain of cause-and-effect configurations that lead to a file showing up on the islandora node's page is one of (if not the) most arcane part of Islandora, that we yet expect new users to be able to extend and configure.

It would also be more intuitive to users of Drupal.

What kind of user is the feature intended for?
(Example user roles: Collections Manager, Developer, Systems Administrator, or User)

Developers and Collection Managers would benefit the most.

What inspired the request?

Many talks with the Islandora community. Up to now, I've been the one holding this back.

What existing behavior do you want changed?

Media point to nodes

Any brand new behavior do you want to add to Islandora?

Nodes point to media, like normal.

Any related open or closed issues to this feature request?

Islandora/documentation#1855