GitLab

This comes with new features:
 - apache-style logs are ingested with fields pre-parsed
 - apache-style logs are enriched with geoip fields
 - mariadb slow log have a field for the query fingerprint, like
   pt-query digest
 - systemd journal can be ingested as logs
 - for known log formats, the timestamps of log events are extracted
   from the log itself, which allows ingesting logs with a delay, but
   also comes with new challenge to get the timezone right for zope logs
   which do not contain a timezone field in timestamps and are in the
   instance timezone. For zope logs, we introduce a `timezone` parameter,
   which is the same as the `timezone` parameter from the ERP5 instance.
   Other logs either include a timezone (apache-style logs) or are in
   local machine timzeone (zeo, haproxy errors), which is the same as
   fluent-bit itself, so no conversion is necessary here.

This prepares the integration of fluent-bit in ERP5, to push logs to
loki like this or wendelin.