Finish components UI

I think it's odd that reaction rules that haven't been overridden yet show up on their admin page, but components do not on their page. Maybe it's because I've embedded the form for the components elsewhere on my site, but I doubt it.

I noticed this when I reverted one of the components I had added conditions to (see #823890: Condition component labels can't be changed). I expected the component to be listed still because it was defined in hook_default_rules_configuration(). I had to go back and add another condition to it through the form I set up before it would show up again in the list.