Support update cookies according to the responses

[gsfish]

This is for accepting cookies from the website during redirections. The --update-cookies option is added to determine whether whatweb shoud use dynamic cookies.

I have recently encountered a case that a website uses SSO and there are serval redirections before getting to the final target. Which means that, in addition to specify the basic cookie using --cookie and --follow-redirect, the client need accept and update cookies from response, and follow serval redirection to complete the authorization.

[urbanadventurer]

Thanks for submitting this PR @gsfish. WhatWeb's cookie handling is currently under review for an update.