Allow django log levels to be controlled with a separate log level setting so GCP logs don't fill up with error messages. Add separate env flag for google cloud log severity setting to filter out INFO if needed.

PR here: https://github.com/HumanSignal/label-studio/pull/5540 - to be used in Dockerfile specifically to allow google cloud logs to look good, as console messages get sent to ERROR. Also would be nice to filter our request logging in general.

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