feat: signature rejection (#1472)

## 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

packages/prisma/schema.prisma

@@ -393,6 +393,7 @@ enum SendStatus {
 enum SigningStatus {
   NOT_SIGNED
   SIGNED
+  REJECTED
 }
 
 enum RecipientRole {
@@ -414,6 +415,7 @@ model Recipient {
   signedAt          DateTime?
   authOptions       Json?
   signingOrder      Int?
+  rejectionReason   String?
   role              RecipientRole @default(SIGNER)
   readStatus        ReadStatus    @default(NOT_OPENED)
   signingStatus     SigningStatus @default(NOT_SIGNED)