local-clock-identity duplicates again

[openBackhaul]

The following attributes seem to be duplicates:

• ptp-sync-pac/ptp-local-clock-identity
• ptp-transparent-clock-default-dataset/local-clock-identity

(Issue #52 is proposing to delete another dublicate in ptp-sync-pac/ptp-default-dataset/local-clock-identity.)

[openBackhaul]

Decision made during the 5G-xhaul call on 26th of July 2023:

The ptp-transparent-clock-default-dataset/local-clock-identity should be deleted from the SyncModel.