Draft: re-added notify_on

This adds again the notify_on attribute.

JOB:
 NOTIFY_ON:
   - RUNNING
   - COMPLETED

Also the

mail:

 to: 
   - mail_1

expects a yaml_list

#1484 , #1468

TODO:

• test in bschubs when working, or any other automail.
• docs
• add pytests if confirmed this is enough

I believe the automail of BSC can't be tested outside the ibsc