Add more "golden questions" to Duo Chat specs

What does this MR do and why?

Include all items from the list of "golden questions" from &10550 that do not require chat history (a future MR will follow to include more questions asking the Chat to expand on previous answers). Note that this MR does not aim to fix the current or added test cases, only to extend our coverage. Note that these specs are currently not executed on CI.

Part of #422212 (closed)

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Before	After

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

See https://docs.gitlab.com/ee/development/ai_features/duo_chat.html#testing-gitlab-duo-chat-with-predefined-questions for local test setup

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

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