fix: Track attachments by URL

Author: szuperaz

projects/stream-chat-angular/src/lib/attachment-list/attachment-list.component.html

@@ -1,6 +1,6 @@
 <div *ngIf="orderedAttachments.length > 0" class="str-chat__attachment-list">
   <ng-container
-    *ngFor="let attachment of orderedAttachments; trackBy: trackByReference"
+    *ngFor="let attachment of orderedAttachments; trackBy: trackByUrl"
   >
     <div
       data-testclass="attachment-container"

projects/stream-chat-angular/src/lib/attachment-list/attachment-list.component.ts

@@ -83,8 +83,13 @@ export class AttachmentListComponent implements OnChanges {
     }
   }
 
-  trackByReference(_: number, attachment: Attachment) {
-    return attachment;
+  trackByUrl(_: number, attachment: Attachment) {
+    return (
+      attachment.image_url ||
+      attachment.img_url ||
+      attachment.asset_url ||
+      attachment.thumb_url
+    );
   }
 
   isImage(attachment: Attachment) {