Update to refactor AuthorAliasRegistry, its sync and test.

test/decentralised_book_index/sync/sync/author_alias_registry_sync_test.exs

@@ -16,7 +16,7 @@ defmodule DecentralisedBookIndex.Sync.DataTransformers.AuthorAliasRegistrySyncTe
       }
 
       assert :ok = AuthorAliasRegistrySync.create_update(attrs, server.id)
-      assert {:ok, saved_alias} = Metadata.get_author_by_id(attrs.id)
+      assert {:ok, saved_alias} = Metadata.get_author_alias_registry_by_id(attrs.id)
       assert server.id == saved_alias.dbi_server_id
     end
 
@@ -30,7 +30,7 @@ defmodule DecentralisedBookIndex.Sync.DataTransformers.AuthorAliasRegistrySyncTe
       }
 
       assert :ok = AuthorAliasRegistrySync.create_update(attrs, server.id)
-      assert {:ok, saved_alias} = Metadata.get_author_by_id(attrs.id)
+      assert {:ok, saved_alias} = Metadata.get_author_alias_registry_by_id(attrs.id)
       assert server.id == saved_alias.dbi_server_id
     end
   end