[Feature] Separate messages and arguments for prompt of chat method in BaseChatModelSetup

[wenjin272]

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Description

Currently, the chat method in BaseChatModelSetup will get arguments from messages extra_args to fill the prompt template, which is not clear.

Are you willing to submit a PR?

• I'm willing to submit a PR!

[weiqingy]

@wenjin272 I came up with a change proposal on this https://github.com/weiqingy/flink-agents/blob/220-design-review/docs/PR-220/220-DESIGN.md Could you please take a look when you get a chance? If it looks good to you, I can help work on this.

[weiqingy]

@wenjin272 The PR has been created: #698 . Could you take a look when you get a chance? Thanks!