Stop storing identifier in JSON

[ghost]

User Story:
Distributions, or any other referenced metastore item, should be independently editable. This should work both through the drupal edit form and the API (updating a distribution object directly).

Acceptance criteria:

• A distribution will follow the normal DCAT distribution schema without being wrapped with an identifier and data property when stored in the database.
• Core schemas that ship with DKAN will reflect this new structure.
• Everything will still work normally after the above has been done on a new installation.

Estimate: 3 days

[akaroleff]

Can I move this issue to done now @dafeder ? It's sitting in the review column on the https://github.com/GetDKAN/dkan/projects/4 board but I believe it to be done. yes?