provide error line and marker of JSON parse error

[nate-moehring]

JSON-Deserializer has terrible error messages, very difficult to debug errors on json file loads. For example, for a trivial json string like this: {"str": Hello World!}, the error message generated would simply be: "Internal error". Yuck.

This change will utilize the information in the Lexer to provide a more helpful error message like this: Internal error

Internal error
JSON parse error in line 1:
{"str": Hello World!}
--------^