Issue #961: Put back accidentally-removed IIIF Manifest alter hooks. (#962)

* Issue #961: Put back accidentally-removed IIIF Manifest alter hooks.

* Address PHPCS errors.

* Address PHPCS errors.

* Addresss PHPCS errors.

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Co-authored-by: Rosie Le Faive <lefaive@gmail.com>

modules/islandora_iiif/src/Plugin/views/style/IIIFManifest.php

@@ -5,6 +5,7 @@ namespace Drupal\islandora_iiif\Plugin\views\style;
 use Drupal\Core\Config\ImmutableConfig;
 use Drupal\Core\Entity\EntityInterface;
 use Drupal\Core\Entity\EntityTypeManagerInterface;
+use Drupal\Core\Extension\ModuleHandlerInterface;
 use Drupal\Core\File\FileSystemInterface;
 use Drupal\Core\Field\FieldItemInterface;
 use Drupal\Core\Form\FormStateInterface;