Confirmation dialog not shown if users exit measure script dialog with esc

[alexdewar]

I've confirmed that this is a bug, at least on my Linux machine -- presumably it's the same on Windows but it would be good to double-check this (and to double-check that any fix definitely works on Windows).

The ScriptRunDialog class overrides the closeEvent method so that we can show users a confirmation dialog if they try to close it while the measure script is still running, to make sure they don't accidentally terminate their experiment prematurely. Bizarrely though, it seeems that you can close the dialog by pressing esc and if you do so then the closeEvent method is never invoked and so the measure script will be stopped without asking for user confirmation.

We should ask for confirmation if the user presses esc too. It might also be worth seeing if there are any other key combinations that will close the dialog without confirmation.

ALSO: I've noticed that "yes" is the default option in the confirmation dialog, so if the user accidentally presses enter at this point, it will stop the measure script. No/cancel should be the default.