External API user can retrieve a Location title for each Location in the deployment

The Deployment API needs to retrieve a Location title for each Location in the order. To support this, the Taxonomy API should in addition to caching a full list of Locations, also cache each Location by Location ID and provide an endpoint to retrieve a single Location(ExternalApiLocation object) from the cache. Each time the location cache refreshes for the Taxonomy API, the per Location ID should also refresh.

This new endpoint should be a GET request to /taxonomyapi/location/

and should return an ExternalApiLocation.