fix and unit test for parsing long numbers in JSON.Parse

JSON.Parse was reading all non-float number values as Java Integers. This caused a parse exception on long values, because they overflowed Integer.

Jackson's getNumberValue() will read float, int, long, etc. properly: "It will return the optimal (simplest/smallest possible) wrapper object that can express the numeric value just parsed."

I switched the org.dynjs.runtime.builtins.types.json.Parse parseValue() to use it for both number token types and added a unit test that covers the issue.