Cast & Crew using "role-specific images" instead of actor images

[BillyBob1354]

TVDB has "role-specific images" for each show (if they where added). This causes the cast and crew for a show to have the wrong images if the role-specific images were downloaded from another show. This especially affects if the cast and crew images were downloaded for an animated show.

some solutions:
1 - if possible, fetch the "Persons" ID from a Series to download the image of the actor, not the image of the actor from the series
2 - the ability to disable TVDB for actor images or prioritize a different fetcher
3 - when TVDB is used make every show have there own actor images instead of the actor images being global