Domain restrictions semantics

[ameshkov]

If the following conditions are true:

• pattern === ANY_URL
• domain resriction is not empty
• resource type ===(SUB)DOCUMENT

Then use the host of the request URL to check domain restrictions.

Test rules:

• $csp=script-src 'none',domain=example.org
• $cookie=test,domain=example.org

In the case when there's no "source" hostname, `$domain` should be checked against the request's host.

[ameshkov]

Currently, we have a workaround for rules with empty pattern and a domain restriction (i.e. $cookie,domain=yandex.ru). We won't need it anymore if we implement this change.