"Fix unresolved comments" in PR attempts to fix non-review comments

When opening a PR in Copilot App, the "Fix unresolved comments" button includes comments that aren't a result of a review which means that comments that are unrelated to the actual changes introduced in a PR will be considered and acted upon by the session.

I'd argue it makes more sense for the action to only target review comments, and not even consider normal comments whatsoever.

There can be any number of workflows that result in posting comments in a PR, but these comments aren't as part of a review. The comments could be test coverage reports, preview environment links and so on, which produce a lot of noise when a session tries to address them.

跟踪 Copilot App 的 "Fix unresolved comments" 操作以及选择 pull request 评论的逻辑。比较 review 评论与普通评论，然后验证仅包含未解决的 review 评论，并忽略 coverage 报告或预览链接等无关评论。

由索引模型根据 Issue 内容生成。