feat: add empty emails for envelopes

packages/lib/types/recipient.ts

@@ -1,3 +1,4 @@
+import { msg } from '@lingui/core/macro';
 import { z } from 'zod';
 
 import { RecipientSchema } from '@documenso/prisma/generated/zod/modelSchema/RecipientSchema';
@@ -110,3 +111,13 @@ export const ZEnvelopeRecipientManySchema = ZRecipientManySchema.omit({
   documentId: true,
   templateId: true,
 });
+
+export const ZRecipientEmailSchema = z.union([
+  z.literal(''),
+  z
+    .string()
+    .trim()
+    .toLowerCase()
+    .email({ message: msg`Invalid email`.id })
+    .max(254),
+]);