feat: add envelopes (#2025)

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.

apps/remix/app/components/embed/authoring/configure-fields-view.tsx

@@ -118,6 +118,7 @@ export const ConfigureFieldsView = ({
       sendStatus: signer.disabled ? SendStatus.SENT : SendStatus.NOT_SENT,
       readStatus: signer.disabled ? ReadStatus.OPENED : ReadStatus.NOT_OPENED,
       signingStatus: signer.disabled ? SigningStatus.SIGNED : SigningStatus.NOT_SIGNED,
+      envelopeId: '',
     }));
   }, [configData.signers]);