Switch VersionAwareAvatarUrlDecorator atlassian-cache Caches to hybrid mode

In Bitbucket Data Center versions up to and including 4.6.0, the VersionAwareAvatarUrlDecorator caches that back project and users avatars are configured in .replicateViaCopy() mode. This means their contents are distributed over cluster nodes, and in order to get, update, or remove a value a cluster node may perform a remote operation to another cluster node.

Beginning with Bitbucket Data Center 4.7.0, these caches are configured in .replicateByInvalidation() mode, so values are cached independently by each cluster node, and invalidations of stale values on other cluster nodes are fully asynchronous. This results in less coupling between cluster nodes, is more scalable, and reduces the chance that delays on one node (e.g., due to very long GC pauses or OS/networking issues) also affect other nodes in the cluster.