Move unit tests from minio -> moto

[Andrew-Dickinson]

Convert unit testing from minio to moto for mocked S3 calls

Also includes some of the docs changes from #710

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 94.11%. Comparing base (9ef7df3) to head (a876e9a). Report is 1 commits behind head on main.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #711 +/- ## ======================================= Coverage 94.11% 94.11% ======================================= Files 82 82 Lines 3415 3415 ======================================= Hits 3214 3214 Misses 201 201 ```

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