Add settings option to increase timeouts during ffmpeg extractions

[Pluckerpluck]

I have a number of fairly large videos on a network drive. This network drive is not particularly fast, and thus I have been unable to exact a good number of the thumbnails and filmstrips as the drive times out.

I was able to easily bypass this by running the this project locally (thank you for providing the source!), but I suggest providing some way to increase the timeouts.

I would also suggest actually popping up errors if they occur like this. Perhaps adding some toast errors that you can trigger, though I recognise that's a little more annoying given that this process is done in a worker thread. I'm also happy to try implementing any changes myself (though I don't have much time), but I would need to know how or what you'd like implemented here.