AttributeValueDataPacketFinishInitializationAsync Method
Deserilization of a AttributeValueDataPacket is handled by the overridden ReadJson()
method of AttributeValueDataPacketConverter class. Because to deserialize an AttributeValue
the Definition of the Attribute must be known. And reading the Definition is an IO bound
Async call. But ReadJson() is not Async and can't be made async because it is overridden.
To get around this limitation, the Task is assigned to AttributeValueTask (instead
of awaiting and assigning to AttributeValue. The awaiting of AttributeValueTask
is then handled in an async call sepeartly.