fix(amazonq): use current file content to calculate highlighted ranges

[atonaamz]

Problem

The unifiedDiff from suggestionResponse is outdated due to the change of context, resulting to the wrong line getting highlighted while rendering.

Solution

Calculate the addedLines and removedLines using the current code content and new code suggestion.

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[amazon-inspector-ohio]

⏳ I'm reviewing this pull request for security vulnerabilities and code quality issues. I'll provide an update when I'm done

[github-actions]

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