Support Purge instance

[shreyas-gopalakrishna]

• Update the SqlOrchestrationService class to Implement the IOrchestrationServicePurgeClient interface and map it to the existing PurgeOrchestrationHistoryAsync method.

Reference: https://github.com/microsoft/durabletask-java/issues/10 Sample Implementation PR for AzureStorageOrchestractionService: https://github.com/Azure/durabletask/pull/704