Clear separation between basegame and mods

- Always force a page seperation between the last core files cup and the first modded cup
- Lost and Found sits exactly between them
    - If any cup on the last page of basegame is unlocked, place LnF on the last core page
    - Else, LnF is the first "cup" on the first Modded page
    - It's done this way so no Core material is spoiled if you haven't unlocked it yet. We want people to believe RR contains only 7 cups unless they go above and beyond

Also address Volt's bug report: Prevent the first page of cups from being overridden if everything is locked