Use replica path when processing replication jobs

Praefect begins generating relative paths in 14.6. In order to ensure replication RPCs end up targeting the correct repositories on the disk, this commit changes the replicator to use the stored replica path for the various RPCs. Renames and deletes are handled in the old manner as they won't be produced anymore from 14.6 onwards and are left in place only for backwards compatibility. Rest of the replication operations now target the stored replica path instead of the relative path the clients use to access the repository.