Decide how to expose parameters for question and qnaId

@KrzysztofCwalina @tg-msft @schaabs it came up in review that we should move required parameters out of KnowledgebaseQueryOptions and put them as required parameters, which is either string question or int qnaId. Agreed? How does that differ from EncryptParameters for Key Vault, though?

Also, since not all languages support overloads, I propose adding just a GetQuestionAnswer(string projectName, int qnaId, string deploymentName = null). when a qnaId is passed, it’s the only option that matters.

/cc @annatisch @rokulka

_Originally posted by @heaths in https://github.com/Azure/azure-sdk-for-net/pull/21810#discussion_r664912422_

[johanste]

Gut reaction, I think the overloads look good. Let’s try them out!

[heaths]

@annatisch or @johanste could you summarize what you’re thinking for Python? For .NET, I’m leaning toward:

Response<KnowledgebaseAnswers> QueryKnowledgebase(
  string projectName,
  string question,
  QueryKnowledgebaseOptions options = default,
  CancellationToken cancellationToken = default);

Response<KnowledgebaseAnswers> GetQuestionAnswers(
  string projectName,
  int qnaId,
  CancellationToken cancellationToken = default);

/cc @tg-msft @KrzysztofCwalina @rokulka