[HTTPS-Everywhere] Rules not loaded until website is visited

[Jacob Hoffman-Andrews]

I can work on this fix. A question: What do you think of having text
in the list area that says "type a domain to search for," and showing
only the rulesets whose targets match the query? Now that we have 10k+
rules, displaying them all in a list doesn't make as much sense. A
user who really wanted to see the whole list could type "."