Extend IStorage interface to support new operations

[sw-joelmut]

Fixes #848

Description
This PR extends the storage system by introducing IStorageV2 interface to support new operations with structured result types. It adds a StorageCompatibility helper to maintain backward compatibility while enabling enhanced storage capabilities.

Key changes

• New storage interface: Added IStorageV2 interface that extends IStorage with new methods returning structured results (StorageOperationStatus, typed values)
• Compatibility layer: Introduced StorageCompatibility class to convert between IStorage and IStorageV2, ensuring existing code continues to work
• Storage implementations: Updated MemoryStorage, BlobsStorage, and CosmosDbPartitionedStorage to implement IStorageV2
• Component updates: Modified AgentState, UserAuthorization, AzureBotUserAuthorization, ConfigurationAgentHost, and other components to use IStorageV2 and handle structured storage results
• Enhanced operations: Storage operations now return status codes (Succeeded, NotFound, Conflict) and typed values instead of nullable objects
• Test coverage: Updated existing tests and added new tests for IStorageV2 functionality

Testing
The following image shows a few of the tested scenarios.

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