Moves require-loaded class to routing scripts

Moves adding of “require-loading” class to scripts that run at specific
page routes. rspec testing wasn’t waiting for asynchronous scripts to
load, which led to sporadic test failures. This makes the addition of
the class redundant across multiple scripts, but handles notifying of
async scripts being ready.
Test cleanup

Removes unnecessary code in scripts and fixes outdated code comments.
Updates cassettes