Pause game on steam overlay toggle

[Anna Bakker]

The game pauses when it is alt+tabbed out of it, but not when shift+tab is used for the steam overlay toggle, which should pause the game.

[Edward Hart-Davis]

Indeed, the game should pause by default but perhaps should at least be configurable to maintain the current behavior.

[Riot]

This could in theory be achieved with the new SteamStorm, using the GameOverlayActivated_t callback; some experimentation will be necessary.

https://partner.steamgames.com/documentation/game_overlay#activating