The audio output is still messed up, but this commit gets everything as
ready as it can get. Fixed up all the testbenches and added state
machines for everything
I moved around where packages are. I couldn't find any evidence of where
other people put them, but for now they are in the `lib/` folder. Other
infrastructure changes are that all the weird includes we need to make
the linter happy are gated behind ifdefs, so they don't mess with
vivado.
I kinda can't believe concurrent assertions work because there's so
little info about them, good to ssee they actually do something
