Clean up file/directory structure and some code style consistency updates

[darwinz]

This update focuses mostly on the following updates

• Using a more consistent pattern with directory names
• Created directories in tests that correspond to the algorithms that have already been added
• Added tests where they were missing - all algorithms should have tests now
• Some updates to code style - trying to keep the style mostly consistent throughout the repo and following the PSR-12 and PER style guides