Use the NBN API to get UKSI taxonomy data while we lack a usable NHM API?

[jrdh]

@bwprice made the excellent suggestion that we could maybe use the NBN API to get to the UKSI taxonomy.

Two ideas:

• page through all the data from https://species-ws.nbnatlas.org/search?fq=idxtype:TAXON&pageSize=100&start=0 and pass it through the same graph-based importer we have at the moment (is idxtype:TAXON valid? Bit of a guess but it looks good).
• use the NBN API directly from the frontend (upside: don't have to store the data, always up to date, downside: if NBN is down, problem, performance possibly, is there an endpoint we can actually use to get the data (I guess the one above but with fq=parentGUID:parentID)).

[jrdh]

Ok this absolutely works. I've hacked it in to test but I'll tidy up the code and replace the DwC-A reader with the NBN API streamer soon.

[jrdh]

Changed here: https://github.com/NaturalHistoryMuseum/ukbol/commit/083633e006a7aa5e2f22e754488a9bd1b2301ef3