Nodes a script uses through a path of several nodes are marked unique in their
scene and found with %Name. The search list is renamed SearchResults, and the
player row's nodes get their real types.
Every popup is now called *Popup instead of *Window in its file, root node,
node name, class and variable, and PopupWindow becomes BasePopup. Player is
PlayerRow, SongListObject is SongRow and Character is CharacterCard. Script
files are snake_case and scene files PascalCase, each matching its class or
root node, and LightGrayTheme.tres is light_gray_theme.tres.