feat: Log the flow.run_local_server redirect URL

[mafrosis]

When running this library in a headless environment, it's often the case that print is not captured and delivered to the end user. By also logging the auth_url, a user of this library could ensure that the auth url reaches the logs.

Also set the module's logger level to INFO, as it was hanging as NOTSET in the current implementation.

I'm unable to run the full nox suite locally, but it looks like nothing has broken. I'll make any changes needed when the CI tests run.