Co-authored-by: Igor Abdrakhimov <igorabd@amazon.com>
Co-authored-by: Michael Graeb <graebm@amazon.com>

Co-authored-by: Michael Graeb <graebm@amazon.com>

**Issue**
A recent PR #1170 (comment) fixed an indexing-math bug in this test. When I took a closer look at this test, I noticed it was broken ... and didn't make much sense

**Research:**
This hash table test was added with the original hash table PR #17.

That branch had 2 different authors, which seems to have led to the brokenness
- Original [commit](c2a7f08) with this test
- In this [commit](ab4e987), author B accidentally replaces floating-point-rand with integer-rand, breaking randomness so this test doesn't actually test anything anymore
- In this [commit](fe71f05), Author A removes some `entries[i -1]` checks that don't really make sense because `entries` isn't sorted
- In this [commit](a36d2dd), Author B brings the checks back. My guess is there was a merge conflict and they just accepted their own side

**Description of changes**
- Fix randomness
- Add comments about what this test is doing
- Fix the checks, using the `sorted_entries` array instead of the unsorted `entries` array