creating queryIterable method

[Farenheith]

The added method aims to offer a seamless way to obtain paginated results from Athena through the async iterable contract.

It abstracts the nextToken manipulation making the call for paginated results much simpler, like in the example below:

async function main() {
    const results = athenaExpress.queryIterable("SELECT * from students LIMIT 100", 10);
	for await (const page of results) {
    	  console.log(page.Items);
	}
}
main();

The default pagination value (the method second parameter) is 999, because 1000 are throwing an error due to the paginationFactor treatment in the getQueryResultsFromS3 method.