Since the job error log can contain information from many different
sources and also from many different jobs it is important to ensure
that visibility of the job error log entries is restricted to job
owners.
This commit extend the view `timescaledb_information.job_errors` with
role-based checks so that a user can only see entries for jobs that she
has permission to view and restrict the permissions to
`_timescaledb_internal.job_errors` so that users only can view the job
error log through the view. A special case is added so that the
superuser and the database owner can see all log entries, even if there
is no associated job id with the log entry.
Closes#5217
5661ff1523