[TLC-674] Properly test for existence of duplicates section

Author: kshepherd

src/app/shared/object-list/my-dspace-result-list-element/pool-search-result/pool-search-result-list-element.component.ts

@@ -76,8 +76,6 @@ export class PoolSearchResultListElementComponent extends SearchResultListElemen
    */
   showThumbnails: boolean;
 
-  enableDetectDuplicates$: Observable<any>;
-
   constructor(
     protected linkService: LinkService,
     protected truncatableService: TruncatableService,
@@ -101,14 +99,6 @@ export class PoolSearchResultListElementComponent extends SearchResultListElemen
       followLink('submitter')
     ), followLink('action'));
 
-    // Get configuration for duplicate detection feature
-    this.enableDetectDuplicates$ = this.configService.findByPropertyName('duplicate.enable').pipe(
-      getFirstCompletedRemoteData(),
-      map((rd: RemoteData<ConfigurationProperty>) => {
-        return (rd.hasSucceeded && rd.payload && rd.payload.values[0] === 'true');
-      })
-    );
-
     (this.dso.workflowitem as Observable<RemoteData<WorkflowItem>>).pipe(
       getFirstCompletedRemoteData(),
       mergeMap((wfiRD: RemoteData<WorkflowItem>) => {

src/app/submission/objects/submission-objects.effects.ts

@@ -449,7 +449,7 @@ export class SubmissionObjectEffects {
         // or if configuration overrides this behaviour
         if (!alwaysDisplayDuplicates()) {
           const duplicatesSectionId = findKey(currentState.sections, (section) => section.sectionType === SectionsType.Duplicates);
-          if (isNotUndefined(duplicatesSectionId) && isEmpty((sections[duplicatesSectionId] as WorkspaceitemSectionDuplicatesObject).potentialDuplicates)) {
+          if (isNotUndefined(duplicatesSectionId) && sections.hasOwnProperty(duplicatesSectionId) && isEmpty((sections[duplicatesSectionId] as WorkspaceitemSectionDuplicatesObject).potentialDuplicates)) {
             mappedActions.push(new CleanDuplicateDetectionAction(submissionId));
           }
         }

src/app/submission/objects/submission-objects.reducer.ts

@@ -862,7 +862,7 @@ function deleteFile(state: SubmissionObjectState, action: DeleteUploadedFileActi
 }
 
 function cleanDuplicateDetectionSection(state: SubmissionObjectState, action: CleanDuplicateDetectionAction): SubmissionObjectState {
-  if (isNotEmpty(state[ action.payload.submissionId ])) {
+  if (isNotEmpty(state[ action.payload.submissionId ]) && state[action.payload.submissionId].sections.hasOwnProperty('duplicates')) {
     return Object.assign({}, state, {
       [ action.payload.submissionId ]: Object.assign({}, state[ action.payload.submissionId ], {
         sections: Object.assign({}, state[ action.payload.submissionId ].sections, {