Support strings surrounded by double quotes

JMS:
> A string literal is enclosed in single quotes, with an included single quote represented
> by doubled single quote; for example, 'literal' and 'literal''s'.

AMQP SQL
https://docs.oasis-open.org/amqp/filtex/v1.0/csd01/filtex-v1.0-csd01.html#_Toc67929302
> A string constant is a string of arbitrary text consisting of any valid printable Unicode
> characters surrounded by single or double quotation marks. A quotation mark inside the
> string is represented by two consecutive quotation marks.
> string_constant ::= { ‘ | “ } <any> [<any>] { ‘ | “ }

Author: ansd