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.
## Description
Adds support for rejecting a given document informing the document
owner.
Flows for resolving a rejection don't currently exist so it's up to the
document owner to reach out to the recipient and work out a way to move
forward via a new document or offline agreement.
## Related Issue
## Changes Made
- Added new rejection properties to the recipient schema
- Added API endpoints to support rejection
- Added email templates for notifying the document owner and recipient
- Added a dialog on the signing page to start the rejection flow.
## Testing Performed
- Manually tested the flow end to end
- Automated tests are planned
