fix: 🐛 Fix multiframe images (#1595)

Co-authored-by: Danny Brown <danny.ri.brown@gmail.com>

platform/core/src/classes/metadata/StudyMetadata.js

@@ -78,7 +78,7 @@ export class StudyMetadata extends Metadata {
     Object.defineProperty(this, 'studyInstanceUID', {
       configurable: false,
       enumerable: false,
-      get: function () {
+      get: function() {
         return this.getStudyInstanceUID();
       },
     });

platform/core/src/utils/StackManager.js

@@ -35,7 +35,8 @@ function createAndAddStack(stackMap, study, displaySet, stackUpdatedCallbacks) {
       imageIndex: imageIndex + 1,
     };
 
-    const NumberOfFrames = image.NumberOfFrames;
+    const naturalizedInstance = instance.getData().metadata;
+    const NumberOfFrames = naturalizedInstance.NumberOfFrames;
 
     if (NumberOfFrames > 1) {
       for (let i = 0; i < NumberOfFrames; i++) {
@@ -60,8 +61,6 @@ function createAndAddStack(stackMap, study, displaySet, stackUpdatedCallbacks) {
       imageId = getImageId(image);
       imageIds.push(imageId);
 
-      const naturalizedInstance = instance.getData().metadata;
-
       const {
         StudyInstanceUID,
         SeriesInstanceUID,