Improve post & events cards, homepage and my events page

Signed-off-by: Thomas Citharel <tcit@tcit.fr>

js/src/components/Resource/FolderItem.vue

@@ -61,7 +61,7 @@ export default class FolderItem extends Mixins(ResourceMixin) {
   list = [];
 
   groupObject: Record<string, unknown> = {
-    name: `folder-${this.resource.title}`,
+    name: `folder-${this.resource?.title}`,
     pull: false,
     put: ["resources"],
   };