[ENG-8266] Fix "linked item" for linked service configuration (#2591)

Author: cslzchen

lib/osf-components/addon/components/addons-service/configured-addon-edit/template.hbs

@@ -35,6 +35,8 @@
                     {{this.selectedFolderDisplayName}}
                 {{else if this.selectedItemDisplayName}}
                     {{this.selectedItemDisplayName}}
+                {{else if this.isLinkAddon}}
+                    {{t 'addons.configure.no-item-selected'}}
                 {{else}}
                     {{t 'addons.configure.no-folder-selected'}}
                 {{/if}}

translations/en-us.yml

@@ -374,6 +374,7 @@ addons:
         selected-folder: 'Selected folder:'
         linked-item: 'Linked item:'
         no-folder-selected: 'No folder selected'
+        no-item-selected: 'No item selected'
         go-to-root: 'Go to home folder'
         go-to-folder: 'Go to folder {folderName}'
         select-folder: 'Select {folderName} as root folder'