[18.0][ADD] auditlog_stdout: output to a logger instead

[antonioburic]

Adds an option to an auditlog rule to output a log entry to Odoo's logger, instead of creating auditlog.log and auditlog.log.line records.

why? it's a use case f.e. if you want to log a lot of reads and ingest it into a log management tool (Datadog, ELK etc) without adding many rows to the auditlog tables and burdening performance.