Investigate rollbackEntityOperationsOnExceptions semantics for Durable Entities

Upstream report: https://github.com/Azure/azure-functions-durable-python/issues/274

Investigate whether azure-functions-durable v2 entities honor the host rollbackEntityOperationsOnExceptions setting. This may require a Durable Functions extension or wire-contract change if the setting is not available in the Python entity request.

Investigation goals

• Verify omitted/default and explicit true: set, delete, create, and in-place mutation followed by an exception are rolled back.
• Verify explicit false: those mutations remain applied.
• Verify that, in a multi-operation batch, only the failed operation is rolled back and successful operations before and after it remain applied.
• Verify callers observe the operation failure without an unintended retry.
• Add end-to-end host coverage for supported v2 providers.
• If the gRPC or extension contract cannot carry this option, identify and link the required extension/protobuf work rather than implementing SDK-only behavior.

Start with the upstream report and the Python entity request for Durable Entities v2, then compare it with the host rollbackEntityOperationsOnExceptions setting and the gRPC or extension/protobuf contract. Exercise the listed mutation, batching, failure, and retry cases, followed by end-to-end host coverage for supported v2 providers. Done means the semantics are verified, or the required extension/protobuf work is identified and linked instead of adding SDK-only behavior.