Would be great to have the Open File button when checking a diff from Amazon Q chat

## Problem
Some VSCode features/extensions that allow you to see a diff will have an Open File button to the right of the diff tab (pictured in description). This button allows you to quickly select the original file that the diff is based on. A good example of this is the Source Control feature built into VSCode, which allows you to view a diff for a file, but provides this quick-access button to open the actual file in its current form.

For Amazon Q, there are many ways to see a diff, such as when clicking on the changes to a file in the chat window. However, from this diff, there is no simple way to select the original file. Instead, I need to go look for that file directly, which can slow me down, especially in large projects where many files have similar names (such as `index.tsx` as a common example). Every time I click on the diff, I instinctively expect to see the Open File button, but am disappointed to be reminded that I have to go look for the file myself.

## Expected behavior
When opening a diff tab from the Amazon Q chat (which contains `(Generated by Amazon Q)` on the tab header), there should be a button or other quick way to open that actual file, as is available in other VSCode features that provide diffs, such as Source Control.

No files or tests are named. Start by locating the Amazon Q chat flow that opens diff tabs containing “(Generated by Amazon Q)” and compare its behavior with VS Code’s Source Control diff; done means the diff offers a quick action that opens the original file.

Written by the indexing model from the issue text.