Feature and motivation
Problem: To get cookie by name we fetch all cookies and then filter them out internally.
Spec: https://www.w3.org/TR/webdriver2/#get-named-cookie
Usage example
C#:
driver.Manage().Cookies.GetCookieNamed("abc");
Solution
This method should send GET /session/{sessionId}/cookie/{name} request. {name} is not null or empty, otherwise remote end returns the list of all cookies.