Generate these assets in config because this package is imported by
most.
Add internal/addgenheader as a simple helper because go-bindata doesn't
output the write header.
Also update test CI workflow to regenerate and check commit is clean.
This workflow does nothing, but we need an initial workflow in place in
order to be able to iterate and test with changes to that workflow in
later PRs. Hence we commit a simple "Hello, World!" workflow for now
that will be refined in later PRs.