Auxio should fetch cover for albums with multiple folders

[gfh4550]

Description

For example u can use "Music To Be Murdered By - Side B"

• I have checked this feature request for duplicates.
• I have checked that this feature is not implemented in the lastest version.
• I have checked the Why Are These Features Missing? page.
• I agree to the Contribution Guidelines.

[OxygenCobalt]

Can you please elaborate on what you mean @gfh4550?

[PetbkA]

I guess that @gfh4550 wants that for structure:

• Album
  • CD1
  • CD2
  • Cover.jpg

both of CDs were using Cover.jpg if there's no Cover.jpg in their folders.

Nice feature, but pretty niche, and I don't remember it implemented in any music player

[OxygenCobalt]

Ah, that makes sense @PetbkA, will roll into #104.