Fix Importing Compendiums breaking folder structures

[adracea]

Removed folder from the list of keys to be deleted when importing compendiums. This was causing issues when importing nested compendiums such as:

• [Items]
  • [Weapons]
  • {Sword}
  • {Gun}
  • [Ammo]
    • {Gun Ammo}

To end up being imported as:

• [Items]
  • [Weapons]
  • [Ammo]
  • {Sword}
  • {Gun}
  • {Gun Ammo}

[moo-man]

Sorry, closing this as I've refactored the keepID override into a much cleaner implementation than before.