match_to supports arrays!

I've found myself wanting to use an array in `match_to` a few times, so this lets us do that. It accepts an array of nodes or IDs.

While not always the most efficient way of doing things, it lets you do things like this:
```ruby
current_user.shows(:s, :r).rel_where(auth: 99).bands.match_to(other_user.bands.to_a).pluck(:s)
```
"Return current user's shows where their auth level is 99 and the bands playing include any of this other user's bands." n + 1, but fast and easy to write. In the future, I'd love to see if we could do this in a single query from QueryProxy.