Add support for N1QL

[TMWilds]

N1QL, is a query language for the Couchbase NoSQL database.

While similar to SQL, the classifications of keywords, operators and booleans differ. There are also some structural differences. This means using the SQL syntax highlighter doesn't quite hit the spot.

I already have a pull request ready to go, but realised I had no issue to link it to. I will raise the request soon!