feat: added error obj for admin status users on deletion

packages/hoppscotch-backend/src/errors.ts

@@ -10,6 +10,14 @@ export const DUPLICATE_EMAIL = 'email/both_emails_cannot_be_same' as const;
 export const ONLY_ONE_ADMIN_ACCOUNT =
   'admin/only_one_admin_account_found' as const;
 
+/**
+ * Admin user can not be deleted
+ * To delete the admin user, first make the Admin user a normal user
+ * (AdminService)
+ */
+export const ADMIN_CAN_NOT_BE_DELETED =
+  'admin/admin_can_not_be_deleted' as const;
+
 /**
  * Token Authorization failed (Check 'Authorization' Header)
  * (GqlAuthGuard)