Disable mouse highlight when using keyboard

[HiddeKoerts]

For keyboard users, the highlighting of the card over which the mouse hovers can be distracting. This occurs somewhat regularly, as the last mouse movement often relates to interaction with the lobby, e.g. the chat or starting the game itself.

Ideally, the mouse would only highlight a card after it has been moved during the game (or even after it has moved of the first card its hovering over at the start of the game). Alternatively, it might be easier to implement a setting allowing the user to disable the highlighting all together. Note that I do not mean the actual selected card, just the card that the mouse hovers over.