Set primary writer/artist for CBL tags

To list the primary writer/artist in CBL's library, they need to be set as primary. It'd be great if ComicTagger could do this automatically. For example, if there's only one writer, then could ComicTagger set that to primary? And if there's only one penciler, could ComicTagger change that to artist and set it as primary? In the case of multiple writers/artists, maybe a prompt asking you to choose a primary, if wanted?

I did just add this feature, in a way, in the last release. If you go to settings, and "Comic Vine" tab, you'll see the option "Assume Lone Credit is Primary". When fetching the data from Comic Vine, CT will automatically mark lone writers as primary, and mark a lone artist as primary. It will move on to copy a lone penciler credit as a primary "Artist".

This works only when Comic Vine data is fetching from online, though.

I am thinking I need to add some sort of "migration smarts" for the metadata, when moving metadata between tag styles, handling this case, and maybe moving other data into the CBL catch-all "Tags" field. Just not sure of the right way to do it yet...