reconsider the way we specify controls on the map

I'm sure I've missed some previous discussions on this, but to me it feels a bit unnatural to have every control be specified as a boolean on the map config, and having its options also directly in the map's config. This really bloats the map config object and makes it hard to structure.

Why was it decided not to just pass in controls as a collection of controls like this was done in ol2? Because it requires re-specifying the default controls?