log: should expose global state

[apowers313]

Is your feature request related to a problem? Please describe.

When developing a system with a large number of dynamic components (e.g. extensions, modules, libraries) the names of the loggers may not be known in advance or may require extensive work to deep dive code and aggregate a list of logger names.

Instead, the log module should expose its internal state allowing developers to programmatically identify all created loggers. This would also enable dynamically adding handlers, changing handler configurations (such as log level), programmatically changing the log level for all created loggers, programmatically changing the log level for loggers matching some pattern, etc.

Describe the solution you'd like

log.handlers and log.loggers as getters for the internal state Maps.

Happy to put together a PR if this is an acceptable direction.

[denizdogan]

Did anyone ever take a look at this?

[kt3k]

This might be in a similar direction #2399