ViewDescription default Timestamp value should be OPC UA TimeBase

[cacamille3]

OPC UA TimeBase is 1601-01-01 UTC
Otherwise, some OPC UA Server not supporting this Browse optional feature might return BadViewTimestampInvalid when the Timestamp is not set to null

#654

[cziebuhr]

You can't just do changes in uaprotocol_auto.py, as it gets autogenerated.

https://reference.opcfoundation.org/Core/Part6/v105/docs/5.1 has a table with default values per built-in type. I think it makes sense to use all those defaults in all places where default values gets created:

• common/structures104.py:get_default_value
  • Boolean: "False" (instead of "True")
  • DateTime: "FILETIME_EPOCH_AS_UTC_DATETIME"
• ua/uatypes.py:get_default_value
  • ByteString: null (instead of b"")
  • DateTime: FILETIME_EPOCH_AS_UTC_DATETIME

(List may not be complete)

[oroulet]

but you can simply move that code uaprotocol_hand.py or similar that overrides autogenerate classes. We do that already for a few classes