Reduce duplication between v1 and v2 process-test-directory builders

[howard-e]

[...] on duplication between lib/data/process-test-directory.js and lib/data/process-test-directory-v1.js [...]:

v1 csv resources and references eventually won't exist so there won't be a need to build them. A couple v1 files have already been removed since introducing v2

So separating that into dedicated orchestrating scripts for the v1 and v2 test formats rather than creating branches in a single file that we may want to eventually prune in the future seemed much easier to do

Some parts are similar enough though that the functions could be consolidated in a single util and used separately

[...]

Originally posted by @jugglinmike in #907 (review)