VTM version 4.2

MMVD simplification by removing the two largest distance entries in the
MMVD distance table using encoder only change method.
To make the number of MMVD distance entries configurable by the
software, additionally adding 'MmvdDisNum' as a new option in the cfg files.

includes:
- rename flag HandleCraAsBlaFlag to HandleCraAsCvsStartFlag
- changes of NAL unit types (reduced number)
- profile_tier_level and general_constraint_info structures

Relying on dead function