[SPARK-55691][CONNECT] GetStatus client

[terana]

What changes were proposed in this pull request?

Client-side implementation of the GetStatus API:

• Add client methods for requesting operation statuses.
  • GetStatus API is designed to support other request types that operation statuses in future. For those types, new methods will have to be created. This is a tradeoff between convenient client methods which encapsulate the most of the request building and flexibility.
• Mark the client methods as Experimental and underscored for now, until enough confidence in the API stability is built.
• Add client tests with mocked service.
• Add E2E tests with real operation lifecycles.

Why are the changes needed?

GetStatus API allows to monitor status of executions in a session, which is particularly useful in multithreaded clients.

Does this PR introduce any user-facing change?

Yes. It's a new Spark Connect API.

How was this patch tested?

• Add client tests with mocked service.
• Add E2E tests with real operation lifecycles, which also test server-side changes.

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