Global logging format changes

[peytondmurray]

Why are these changes needed?

This PR changes how the logging configuration for Ray is set, and changes the format of log messages.

After a discussion with @rkooo567 we've decided to split the logging changes into multiple PRs. This is the first in a series which makes changes to library-level logging code for Ray.

Changes

• Attempts to consolidate logging configuration by introducing reasonable defaults in ray/log.py.
• This new logging configuration is done once in ray/__init__.py at the top of the module. Subsequent calls to the configuration are ignored.
• A logger for ray.rllib is configured at the WARN level, to address Revert "Simplify logging configuration. (#30863)" #31858. With this change,
  Revert "Simplify logging configuration. (#30863)" #31858 can be reverted, again simplifying and consolidating logging configuration.
• Modified test_output.py::test_logger_config to test only the logger config, not launch a ray cluster. The test was failing intermittently, I think due to a race condition between the launch of the cluster and the reading of the subprocess's stdout, and anyway it wasn't necessary to call ray.init here to check that logging was configured correctly.
• Modified python/ray/tune/tests/test_commands.py::test_ls_with_cfg to test the underlying data, not what gets printed to stdout (which has changed with the new logging system).
• Modified a logging message in ray.tune.automl.search_policy.AutoMLSearcher.on_trial_complete, which in certain cases emits a logging message which tries to format a NoneType into a %f during log message formatting. This was a previously-undetected bug which showed up because the default log level is now INFO. This fixes a test that was failing in test_automl_searcher.py::AutoMLSearcherTest.

Related issue number

Partially addresses #30005.

Checks

• I've signed off every commit(by using the -s flag, i.e., git commit -s) in this PR.
• I've run scripts/format.sh to lint the changes in this PR.
• I've included any doc changes needed for https://docs.ray.io/en/master/.
• I've made sure the tests are passing. Note that there might be a few flaky tests, see the recent failures at https://flakey-tests.ray.io/
• Testing Strategy
  • Unit tests
  • Release tests
  • This PR is not tested :(

[peytondmurray]

Failing tests

• Windows build and tests fail due to an issue creating a file - I'm assuming this is some permissions issue on the CI runner:

[Errno 2] No such file or directory: '::test_list_named_actors_namespace.txt'

• There are also several test suites which fail for some other unrelated issue:

Error: Observed wheel commit () is not expected commit (3941de4b770d0b904ec720ddd42555cc200f9f7d). Aborting.

[rkooo567]

Please add me to the assignee section!

[peytondmurray]

☝️ Sorry about that! I saw your name in the assignee section, I should have added you to the reviewers as well!

[peytondmurray]

Rebased onto master to pull in the new test fixes for rllib.

[rkooo567]

Can you add unit tests? We should make sure

1. The context is properly printed within each library
2. make sure the logging_level and logging_format works after this PR

I will also play with this log once I come back from OOO (next Mon)