Fixes Bug890650 crashes by user build

Fixes a bug in rapid beta that causes NULLs to be present in the product_version_id field when querying for rapid beta-enabled versions. 

The problem stemmed from the renaming of `rapid_beta_id` to `product_version_id` in a sub-SELECT. Later, a SELECT intending to use that column, used `rapid_beta_id` instead because an extraneous join to `product_version` was in the query. 

Reproducing was challenging, but much easier due to fakedata! Now, we will be testing rapid beta matviews with every run of `setupdb_app.py` that includes fakedata.

I included some whitespace cleanup of `update_build_adu.sql` and some additional comments.