Collections: Bulk collection creation

The current REST API which allows creation of single objects (scope/collection) has been observed to take some time to return success to the caller, the impact is that creating a large collection configuration can take a while, perhaps 1000 seconds.

The following users may benefit from an API which allows the client to specify a collection configuration (which has many scopes/collections) in one call.

• Backup (when restoring they need to create collections before uploading data).
• Test users have the need to create a cluster and configure various collections, often maxxing out the configuration.

These users would benefit from a bulk create API