Summary:
Notify user after we hit /reset_password call.
Added case to rerun the original task if it fails due to YBA restart

Test Plan:
Tested following cases -

  - Verified notification being sent after calling /reset_password API
  - Manually added some wait in sendNotificationTask -> reset password -> force kill YBA -> Notification is sent on YBA restart

Reviewers: amalyshev

Reviewed By: amalyshev

Differential Revision: https://phorge.dev.yugabyte.com/D43211