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
General fixes to the email domain features
Changes made:
- Add "email" validation for "Reply-To email" fields
- Fix issue where you can't remove the "Reply-To" email after it's set
- Fix issue where setting the "Sender email" back to Documenso would
still send using the org/team pref
