Add an option to refresh cache when set to visible.

[Etuldan]

Like the https://github.com/obsproject/obs-browser/blob/d6805f53d0c09694807a974e0371bd3ca04cb177/obs-browser-plugin.cpp#L399-L405 , could we have similar feature for https://github.com/obsproject/obs-browser/blob/d6805f53d0c09694807a974e0371bd3ca04cb177/obs-browser-plugin.cpp#L391-L394 ?

I mean, force refresh cache when set to visible ? Will be very helpful when manipulating from websocket. (see https://github.com/Palakis/obs-websocket/issues/339 )

Regards