When using an API key created in a team context, the
documents/templates’ owner always defaults to the team API token
creator, rather than the actual uploader.
For example, John creates the API key for the team "Lawyers". Tom and
Maria use the API key to upload documents. All the uploaded documents
are attributed to John.
This makes it impossible to see who actually uploaded a document.
The new feature allows users to enable document ownership delegation
from the organization/team settings.
This PR is handles the changes required to support envelopes. The new
envelope editor/signing page will be hidden during release.
The core changes here is to migrate the documents and templates model to
a centralized envelopes model.
Even though Documents and Templates are removed, from the user
perspective they will still exist as we remap envelopes to documents and
templates.
