Migrate TypeQLSteps implementation from client-python

[alexjpwalker]

Problem to Solve

TypeQLSteps is bulky, messy, hard to follow and hard to debug when things go wrong.

Proposed Solution

I wrote an improved implementation, in particular of the uniquely identify answer concepts and answer groups are steps, in client-python. It is structured more cleanly, introducing the ConceptMatcher and ConceptMatchResult classes - the latter of which is really powerful for debugging failing tests. We should migrate this code to client-java (and client-nodejs).