improve speed of BulkArea query

[glassbead0]

Querying BulkArea for an entire state is slow. this is because of the N+1 problem when querying for media, climbs, and organizations for each area. To improve perfomance, we should update the code to use a JOIN query to get all the data (areas, climbs, media, organizations), in one query.

[CocoisBuggy]

This issue could be partially resolved with #428 since it brings alternate parent/child representations that wouldn't explode the backend, so I would be happy to resolve this if that gets merged