Feature/filesystem kmp

[aclassen]

Any support rewriting tests is highly appreciated

[digitalbuddha]

I'm ok merging this before tests are backfilled. We won't be doing a release until full conversion is complete and can add tests post merge.

[aclassen]

I'm still working on rewriting the tests, sorry for that. We can merge and i create a separate pr for tests as soon im done.

[digitalbuddha]

No worries. I just wanted to make sure you aren't waiting on me. No rush from my end

[matt-ramotar]

Hey @aclassen Just put up #506 if you want to take a look