Cleaned up getQueryInfo()

Unable to get SQL to work for "grandfathered" case, where trying to
pull all the rows of approved_revs EXCEPT those that meet the
requirements of MediaWiki:Approvedrevs-permissions.

Instead will pull all rows into "grandfathered" case, then filter
them one-by-one using ApprovedRevs::pageIsApprovable(). This can also
be used to add CSS classes to each row, allowing javascript filtering