Clarify cancellation message to avoid confusion for beginners

[pavelwatson]

Is your feature request related to a problem? Please describe.
When you cancel the game on OGS, the message "White wins" and "White wins by Cancellation" is voiced and displayed. This can be confusing, especially for beginners, and misleading them to think they lost ranking points because they canceled the game. This causes unnecessary confusion.

Describe the solution you'd like
The cancellation message should be more neutral and clear. Instead of "White wins by Cancellation", the message could simply state "Game canceled". Additionally, the voice notification should be updated to say "Game canceled" or just removed entirely, to avoid implying that one player lost and the other won.