Add query string to RequestInfo

[valentinbeggi]

Describe the solution you'd like

RequestInfo currently only exposes headers. Add the query string from the original HTTP request:

export interface RequestInfo {
headers: IsomorphicHeaders;
queryString?: string; // e.g., "foo=bar&debug=true"
}

The transports already receive the full request object in handleRequest() - just need to extract and pass along the query portion.

[KKonstantinov]

Agree. This will be factored in in the v2 version of the sdk