The BuildeNB steps either does things that are already implemented
(created workspace), or things that we don't use (separate build_wait),
and is generally quite convoluted when all it does is calling build_oai.
Reimplement by reusing Create_Workspace, and make build_oai in a single
step. To clean up, make a new module in which this function does not
need a class instantiation. Instead, we give all necessary parameters
directly.