The intended purpose for local mode was local storage access without
entering replication hooks. However, the same can be achieved with
high priority mode. Removed replicating mode and use local instead to
denote locally processing clients.
Depending on the DBMS client session allocation strategy the
client id may or may not be available when the client_session
is constructed, therefore there should be a method to assign
an id after construction. Close/cleanup methods were added to
clean up open transactions appropriately.
