Issue reporter should prompt for unsaved changes, or persist changes

[roblourens]

After #59845, I can close the issue reporter with cmd+w, but if I have unsaved changes, they are all lost. It should show a confirmation prompt before losing text.

We might even want this for November, it's frustrating to hit the wrong button and lose work.

[RMacfarlane]

A confirmation prompt should now be shown if you hit cmd+w with text in the title or description without having submitted