Implement LRO rehydration with static method

[live1206]

• Construct RehydrationToken from multiple fields
  • HeaderSource: Indicates where the NextRequestUri locates in the initial response header, it could be OperationLocation, AzureAsyncOperation, Location or None
  • NextRequestUri: The Uri to poll status of the operation
  • InitialUri: The initial Uri of the operation
  • RequestMethod: Http request method of the operation
  • LastKnowLocation: The last known Location value in the response header
  • FinalStateVia: Configuration from API spec, it could be AzureAsyncOperation, Location, OriginalUri or OperationLocation
• For final get of delete LRO with 404, just return empty response with 204 because the delete succeeded
• To support LRO rehydration for both DPG and MPG, add static methods to existing Operation for user to consume

[azure-sdk]

API change check

API changes are not detected in this pull request.

[annelo-msft]

Left a couple of non-blocking comments.

Removing request changes.