Ensure we always emit "error" events instead of throwing errors

[jfirebaugh]

If queryRenderedFeatures is passed an invalid filter, it throws. If it's passed an invalid layer ID (one that doesn't exist in the style), it emits an error event.

Is there a reason these two errors are reported differently or can we use a consistent error reporting mechanism?

cc @mollymerp @lucaswoj

[lucaswoj]

We have decided to always emit, not throw, errors.

[lucaswoj]

We should entirely remove the "throws" branch in this code https://github.com/mapbox/mapbox-gl-js/blob/b3bffe06564dcd031feeba715bd80de36e94f990/js/style/style.js#L689-L690