inital port locking in case port admin state is delivered as unlock in MIB upload

It seems some ONU's indicate their inital PptpEternetUniAdmin state as 'unlock', even though the G988 recommendation recoomends to start in the 'lock' state.

To have consistent states the adapter has first to lock the PptpEternetUni(s) after MIB download and in case the the ONU device state is not set to enable at that time already.

Note: The python adapter implemented such port locking always per default after or before MIB-download. That was originally not done int the openonu-adapter-go as part of run-time optimisation. Now the conceptual approach would be to do that only if 'unlock' is indicated by the ONU and ONU state is not enabled at that time (hoping that this still provides the optimisation in many cases)