feat(NODE-4810): define the new Logger

[andymina]

Description

What is changing?

Defines the new Logger class as described by NODE-3974. This PR handles the options parsing and instantiation of the logger.

Is there new documentation needed for these changes?

What is the motivation for this change?

Double check the following

• Ran npm run check:lint script
• Self-review completed using the steps outlined here
• PR title follows the correct format: <type>(NODE-xxxx)<!>: <description>
• Changes are covered by tests
• New TODOs have a related JIRA ticket

[dariakp]

Almost there

[dariakp]

Please address the comments in the feature_flags file; otherwise, just a few clean up comments on the mongo_logger.test.ts around the severity helpers and defaults; the testing is exhaustive, and there are improvements that could be made there to condense them by analyzing which cases are redundant (i.e., we want to test each component and each severity level at least once, but testing every component with every severity is overkill; likewise, when testing defaults, just one test case where nothing is set and assertions for the default on each expected thing is enough). If we want to just get these changes in, I am not going to insist on reworking the test cases right now (because they do cover everything), but then we'll need to revisit this and rewrite them in a more maintainable way when we go to implement client option handling for these settings.

[avaly]

I can't find any documentation about this new Logger in the API docs or the v5.0.0 changes doc. Where can we read more about this?

[baileympearson]

Hey @avaly - the new logger is still in development, is currently unused inside the driver and is not intended to be consumed yet. Once development is finished, we'll include information and links to relevant documentation in the release notes for whichever release it is a part of.