Add and change logging for flipper initializer

[rmtolmach]

Summary

• This work is behind a feature toggle (flipper): NO

This PR makes the following changes:

• Only send log message about considering removing features if there are any features to consider removing.
• Log when a feature is added. This will hopefully help us figure out what is adding features and where outdated features.yml live.
• Add an extra log in the rescue just to see if we've been hitting errors.

Related issue(s)

• Feature Toggle cleanup va.gov-team#87532

Testing done

There are no unit tests for this work. I will monitor dev and staging logs in datadog post-merge.

What areas of the site does it impact?

Flipper initializer

Acceptance criteria

• I fixed|updated|added unit tests and integration tests for each feature (if applicable).
• No error nor warning in the console.
• Events are being sent to the appropriate logging solution
• Documentation has been updated (link to documentation)
• No sensitive information (i.e. PII/credentials/internal URLs/etc.) is captured in logging, hardcoded, or specs
• Feature/bug has a monitor built into Datadog (if applicable)
• If app impacted requires authentication, did you login to a local build and verify all authenticated routes work as expected
• I added a screenshot of the developed feature

[ryan-mcneil]

🤞

[github-actions]

Backend-review-group approval confirmed.