localities parameter - error handling

[BK01]

Issue:
If the localities parameter includes an incorrect locality spelling it results in a 500 error. This is not an issue with the notLocalities parameter.

Example:
http 200:
https://geocoder.api.gov.bc.ca/addresses.json?addressString=100%20Main%20Street&localities=Penticton

http 500:
https://geocoder.api.gov.bc.ca/addresses.json?addressString=100%20Main%20Street&localities=Pentiton

[cmhodgson]

This happens because there is no match found in the (mispelled) locality, so the BC match gets added, and it has no locality, so the filter breaks on comparison because I missed a null check. After adding the null check you get no match at all. Perhaps we want to increase the smartness of this filter to handle minor misspellings or to provide some kind of error when a locality filter doesn't match to a locality name exactly (or with a misspelling tolerance).