Large payload azure blob externalization support

[wangbill (YunchuWang)]

This pull request introduces support for externalizing large payloads to Azure Blob Storage in Durable Task applications. It adds a new extension package, configuration options, and a sample console app demonstrating the feature. The main changes include new abstractions for payload storage, Azure Blob Storage integration, and updates to the solution and dependencies.

Externalized Payloads Support:

• Added the IPayloadStore interface in Microsoft.DurableTask.Converters to abstract storing and retrieving large payloads out-of-band.
• Introduced LargePayloadStorageOptions for configuring payload externalization, including threshold, connection string, container name, and compression.
• Created the AzureBlobPayloads extension package (AzureBlobPayloads.csproj) to provide Azure Blob Storage-based payload storage, with dependency injection support and gRPC integration. [1][2]
• Updated solution and dependency files to include the new extension and required packages (Azure.Storage.Blobs, System.ComponentModel.Annotations). [1][2][3][4][5]

Sample Application and Documentation:

• Added LargePayloadConsoleApp sample, including project files, code demonstrating orchestration and entity scenarios with large payloads, and a README for setup and usage. [1][2][3][4]

[halspang]

Just some minor stuff.

[Naiyuan Tian (nytian)]

Where is Grpc.AzureManagedBackend.csproj?