Different loggers for different ffmpeg calls in parallel.

**Is your feature request related to a problem? Please describe.**
The ffmpeg.setLogger() function allows users to listen to the output of an ffmpeg call. This can be useful for pulling metadata for instance. However, when running two ffmpeg commands in parallel, the same logger will be used.
It's possible to create another instance of the ffmpeg wrapper, but this would require loading the bundle again, which is quite large.

**Describe the solution you'd like**
It would be useful to provide an optional logger argument in the ffmpeg.run function, or perhaps return the output of ffmpeg when the call resolves. Something like that.

**Describe alternatives you've considered**
My working solution is to create a request queue which is not ideal.