Add environment variable SKIP_CDBVER_CHECK
The compacting of CDB is required only when upgrading from NSO 4.x to 5.x.
In this MR, when SKIP_CDBVER_CHECK=true, skip checking of existing CDB version and compacting of existing CDB. This should be used after existing CDB have been upgraded to NSO 5.0 and later.
This saves about 3 minutes in my production environment on NSO startup.