CookieStorage has been refactored to use HashMap with base domain as the
key. Values of hashmap is vector of cookies.
CookieStorage now has max_per_host which restricts maximum cookies that
can be added per base domain.
Cookie eviction doesnot take place if max_per_host is not reached.
Cookie eviction logic implemented here does following steps
1) Evict all expired cookies
2) Remove oldest accessed non-secure cookie If any
3) When no non-secure cookie exist, remove oldest accessed secure cookie
if new cookie being added is secure. Else ignore new cookie