Authorize the app maintener to see a job
A user could give the permission to the app maintainer to see the logs of a particular job through a button and the possibility to add a message along with it.
Note: depends on the resolution of #164 (if we allow blanket debugging, then app maintainer always have access to user jobs)
Update: blanket debugging is allowed --> JobAuthMixin should allow access to the webapp owner, but only for GET/HEAD requests (so that the developer only have read-only access to the job).