Attach Python logging messages to namespaced logger

[kennknowles]

The python SDK currently uses logging.(info|error|debug|etc) for log messages. This can be disruptive or unexpected when integrating the SDK into existing applications.

I would like to request updating the SDK to enforce automatic module based namespaces in python code (i.e. logger = logging.getLogger(__name__)) so that all apache_beam output can be controlled by an integrating application without the need to modify the root logging configuration.

I'd be happy to submit a PR for this myself.

Imported from Jira BEAM-3523. Original Jira may contain additional context.
Reported by: amilstead.