WIP - #69738916

- Refactor away from instances_reporter_factory to
  composite_instances_reporter
- Modify space_summaries_controller to use bulk api
- Chunk max app requests from CC to HM to avoid NATS message limits
- Return -1 instead of 0 when an error occurs
- Stub bulk api availability check

* Still need to mess with hm9000_client.rb to conditionally use bulk api

Signed-off-by: Julian Friedman <julz.friedman@uk.ibm.com>