Write output to standard error stream

[wonder-sk]

Right now most of the messages from db-sync use print() so they go to stdout - but ideally they should go to stderr, so that then things work when e.g. using docker logs to get information about what's going on in the container.

[stevenjh]

Yep, agree, I'm using in Azure Container instances and the print logs are lost. I've updated media_sync to use the logging libary, then can swap prints for

logging.error(f"Failed to upload {file['path']}: " + str(e))
logging.info("Updating references ...")

And added a debug_level: 20 to the top level of config based on these codes

Intending to pull request through with these changes, but I've got my repo muddled up with local logins etc