test: add test that shows directory stats are not correct

[jtsmedley]

Title

test: add test that shows directory stats are not correct

Description

This PR is in progress, because the test is not yet passing. Changes need to be made to inspect the DAG of a directory to resolve the correct values.

Related https://github.com/ipfs/helia/issues/580

Notes & open questions

Will likely need assistance with ensuring correct values are consistently returned in testing.

Change checklist

• [ ] I have performed a self-review of my own code
• [ ] I have made corresponding changes to the documentation if necessary (this includes comments as well)
• [X] I have added tests that prove my fix is effective or that my feature works