Ability to add just a HOST instead of domain which includes subdomains

[cbuijs]

For now, when adding a domain to a list, it implicitly means "this domains and all subdomains". There are some corner-cases where we maybe just want to add a "host" and not block any sub-domains. This is already possible by whitelisting a sub-domain of a blacklisted domain. Which maybe is enough to fix some corner-cases.

Backburner for sure.

[cbuijs]

Not sure if this makes sense. Probably better to regex it for corner-cases.