gitaly: Sort the tags returned by FindAllTags RPC
The gitlab uses FindAllTags to fetch all tags and it requires to do sorting in-memory after fetch. By this change we provide ability to sort tags on the gitaly side by: tag name in ascending order and creation date in ascending and descending orders. The default remains the same as if no sorting requested - sort by name, so it should not affect any existing clients.
Closes: #3592 (closed)
Changelog: added
Edited by Pavlo Strokov