Improve species lookup

[timrobertson100]

Recording these here but changes in KVS will be needed to address it.

• Stop interpreting rank before calling the species lookup service (see justification) in the production and pre-backbone check pipelines unless it is specifically given in the rank field
• investigate if we have key collisions for e.g. name=foobar and genus=foo&species=bar in the cache because of this.