Allow nested any filter

Ran into an issue where we needed something like "any of these term values [1, 2, 3] but none of these [4, 5]" and couldn't figure out how to do it out of the box with searchkick. Added this :any (or) filter to accomplish this in a nested setting. Let me know if there's some better out-of-the-box way to do it. And thanks as always.