Add a configuration section for monitoring

Context

The monitoring bus, as introduced at !118 (merged), has different parameters for its outputs:

• Type: standard output, file or UNIX domain socket.
• Format: binary or JSON.
• Location: FS location, depending on its type.

This should be part of the server configuration.

Task Description

• Agree on a YAML configuration section for monitoring.
• Parse and handle that new configuration section.

Acceptance Criteria

All the parameters above can be driven via the server configuration file.