Parse omero.logging properties under new Logging heading

[sbesson]

See ome/openmicroscopy#6393, this adds the corresponding changes to the omero config parse [--rst] command so that the properties gets properly parsed and included in a new section under https://omero.readthedocs.io/en/stable/sysadmins/config.html

To test these changes, a server binary needs to be built with the changes from ome/openmicroscopy#6393. Running OMERODIR=path_to_server omero config parse --rst should now include a Logging section with all omero.logging properties descriptions and their default values.

I expect that with the current 5.6.11 release of OMERO.server which does not includes these properties under etc/omero.properties, these additions should be a no-op and not impact the generated documentation.

[will-moore]

Does this PR purely affect the omero config parse command (just for documentation/info) or does it have some other functional effect?

[sbesson]

To the best of my knowledge, the only place where this codepath is used is the omero config parse command. It is certainly exclusively intended for documentation purposes.

[joshmoore]

👍