Use modern unified logging API

[allenhumphreys]

• Removes all usage of os_log in favor of Logger.
• Codifies logging via a protocol to allow globally tuning how logging is done
• PlayerUI is excluded because it does not depend on ConfCore
• Logging is currently in ConfCore but might make more sense as a small package
• The subsystem's we're using don't follow Apple's recommendation of reverse DNS
• Considering a few of the above things, we might want to tweak the subsystem derivation (could just be the main bundle ID by default, as an example)