## Description
Replace the PDF renderer with an custom image renderer.
This allows us to remove the "react-pdf" dependency and allows us to use
a virtual list to improve performance.
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.
David Nguyen
Lucas Smith
Catalin Pit