Update scan queue related code

We should update the scan request and processing code in minecode. This was originally written for an earlier version of scio, which was then adapted to work with the current version of scio. The abstractions created on the purldb side do not match up entirely on the scio side (Scan vs Project) and the api code can use work. In particular, we should do something like this (https://github.com/nexB/scancode.io/blob/main/scanpipe/pipes/purldb.py) when creating the api library.