Add support for double quoted " strings in insert syntax

[BentEngbers]

The special insert syntax should allow for double qoutes " for identifiers.
The following code is a modified copy from the example in the Readme:

let location = "sweden";
let time = "monday";
let report = "sunny";

let (query, args) = query_args!(
    r"
    INSERT INTO weather_reports
        ( $["location", "time", "report"] )
    VALUES
        ( $[..] )
    ",
    Args {
        location,
        time,
        report
    }
);