Automatic update cancellation

[Dastard_Langley]

The automatic update cancellation flow has poor user experience. Once the game is auto-updating, there is a way to cancel this, by pressing escape. There are two issues:

1. This feature is not communicated to the user. The automatic update screen is seemingly completely non-interactive. A user seeking to cancel an automatic update might conclude that cancellation is not supported. This will leave them either unwillingly waiting a potentially very long time, or force-closing the application. Though unlikely to occur, there may well be some edge case where the latter will corrupt files.
2. There is no confirmation prompt. Accidentally pressing escape will immediately cancel the automatic update with no way to recover progress.

These issues may respectively be alleviated by adding a cancel button and a confirmation prompt.