Display information whether a subdomain is preloaded using the includeSubdomains directive

[ExE-Boss]

When checking if a subdomain is preloaded, I’d like to know if it’s been preloaded by a parent domain that has the includeSubdomains HSTS directive and the name of said parent domain, of if it’s been added manually like bugzilla.mozilla.org.

[nharper]

I think that https://github.com/chromium/hstspreload.org/pull/195 will fix this issue.