Allow WKT (Well Known Text) input for types

Currently you have to write your query as a JSON object using GeoJSON, but there's also the WKT format, and the corresponding `ST_GeomFromText` function - it would need a small test to determine if it should be handling JSON or text, but would give more options to users (I find it easier to remember when testing than the JSON formats).

https://en.wikipedia.org/wiki/Well-known_text_representation_of_geometry