[BUG] Fix IIIF Cookbook recipe structures parsing

[Dananji]

Description

structures in the following IIIF Cookbook recipes are displayed inaccurately;

1. https://iiif.io/api/cookbook/recipe/0026-toc-opera/: structured navigation doesn't display the root node with the label "Gaetano Donizetti, L'Elisir D'Amore"
2. https://iiif.io/api/cookbook/recipe/0064-opera-one-canvas/: this recipe has only one Canvas, but Ramp's structured navigation displays it as 2 canvases
3. https://iiif.io/api/cookbook/recipe/0065-opera-multiple-canvases/: structured navigation doesn't display the root node with the label "Gaetano Donizetti, L'Elisir D'Amore"

To Reproduce

For the last cookbook recipe in the list,
Steps to reproduce the behavior:

1. Go to https://ramp.avalonmediasystem.org/?iiif-content=https://iiif.io/api/cookbook/recipe/0065-opera-multiple-canvases/manifest.json
2. Scroll down to structure
3. Observe the structure doesn't display the first item in the Manifest's structures

Expected behavior

• Structured navigation should display all ranges within the structures property in the given IIIF Manifest unless a given Range has no-nav specified as its behavior