[Job Debugging] Approach to notify users when their jobs are in debugging reservation

[ydye]

What would you like to be added:

Ability to notify user through email when their jobs fail and is in debugging reservation.
For example, if user enabled job debugging and then set the email address when submitting the job. User will receive the email as a notify, if the job is reserved for debugging.

Why is this needed:

Users could know the status of their job at the first time.

Without this feature, how does the current module work：

User should monitor their job's log through webportal to ensure whether it's in debugging reservation or not.

Components that may involve changes:

TDB