Add ability to filter by narrator

[retrodans]

A lot of books I listen too have multiple narrators (for example The Discworld books have some version read by tony robinson OR nigel planer). It would be great if the indexing was aware of this.

I can see there is the ability to do this in the audible search query that is used
https://www.audible.co.uk/search?title=the%20colour%20of%20magic&searchNarrator=Tony+Robinson

So I wonder whether we can potential have an option (maybe a checkbox on the config screen) to tell it to use the 'Album Artist' field when making its searches too. I could potentially help by having a go at this and submitting a PR if that helps, although my time is a little limited at present, so wanted to raise this now in case others may also be interested.

[zahroc]

I second this option!