fix(server): delay send mail if retry many times (#13225)

fix AF-2748

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **New Features**
* Improved mail sending job with adaptive retry delays based on elapsed
time, enhancing reliability of email delivery.

* **Chores**
* Updated job payload to include a start time for better retry
management.
* Added an internal delay utility to support asynchronous pause in
processes.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

packages/backend/server/src/base/utils/promise.ts

@@ -1,3 +1,5 @@
+import { setTimeout } from 'node:timers/promises';
+
 import { defer as rxjsDefer, retry } from 'rxjs';
 
 export class RetryablePromise<T> extends Promise<T> {
@@ -48,3 +50,7 @@ export function defer(dispose: () => Promise<void>) {
     [Symbol.asyncDispose]: dispose,
   };
 }
+
+export function sleep(ms: number): Promise<void> {
+  return setTimeout(ms);
+}