Created an adapter for the Canterbury region in New Zealand

[magsyg]

Created a fetcher for the Canterbury region in New Zealand, currently has around 10 stations, and uploads pm25, pm10, so2, no2 and co. Data is raw and stationary.

I had to manually add the metadata and coordinates based on the map here: https://ecan.govt.nz/data/air-quality-data/, source says it has maybe around 30 stations, but only 10 of them seems to be currently active, I am not certain of the stability of this source.

Should close #650