Support for supplying image-data as a blob

[muesli]

Would be nice if beeep offered a way to supply raw image data as a blob.

[gen2brain]

I think it is only possible on Linux, but will need to check, I remember it was possible to send image-data as a hint, which contains raw data. For Windows and macOS don't think there is a way.

[muesli]

I guess we could generate a temporary file that gets deleted again when the notification expires on other platforms. Frankly though, I'm not sure where I'd rather implement that. In a central place like beeep, which probably knows best how to handle image data in a cross platform fashion and when the notifications expire - or in each individual app separately.

I guess I can see good arguments for both sides.

[gen2brain]

It seems that both Linux and Web can work with bytes, so that is like 50% so I guess it makes sense to handle bytes here. Not sure what is the best approach, to make appIcon an interface? For actions, I thought something like NotifyWithActions or similar can work but this is a different case.