We now require CoreNLP listening on port :9000. We will have to find
a way to spin that up in CI as well.

This commit refactors the codebase to add a new function called
`addDocumentsToHyperCorpus` which generalises the common pattern of
calling `insertMasterDocs` and later adding the documents via the DB
`Doc` functions.

It also "lowers" some functions to run into a plain `DBCmd`.

Alas I (Alfredo) had to split the runners for tasty and hspec because in
tasty we cannot control explicitly the level of parallelism, but for the
DB stuff we need sequential tests, whereas for the Jobs tests we need
parallelism, or rather the executable to be compiled with `-threaded`.