Change backdrop URLs to support sections in a service

Previously we had one bucket for licensing. Journey data has gone into
another bucket. This change rearranges the URLs slightly so that the two
buckets are distinct but under the same service name.

The new URLs for this are.
/performance/licensing/api/application
 - bucket licensing
 - previously at /performance/licensing/api
/performance/licensing/api/journey
 - bucket licensing_journey

See also https://github.gds/gds/puppet/pull/589