Export correlation generation and injection functions
Relates to gitaly!1869 (comment 297124766)
This exports correlation ID generation and context injection functions for use in Praefect. The ID generation is needed to create a correlation ID consistent with existing practices. The injection is needed to enable injection outside of gRPC interceptors (Gitaly needs this ability when fetching a persisted replication job from the datastore). See issue gitaly#2461 (closed) for more details.
Edited by Paul Okstad (ex-GitLab)