Updating Converse upstream (with bootstrap5):

* bootstrap 5 compatibility
* other Converse updates integration
* hack to get the sidebar work as with Converse v10.
* modal onHide was renamed close.
* fix slow mode infobox margin.
* fix margin
* shorter action label, for better dropdown UX.

conversejs/custom/plugins/tasks/templates/muc-task-lists.js

@@ -24,7 +24,7 @@ export default function tplMucTaskLists (el, tasklists) {
       })
     }
     <form class="converse-form" @submit=${el.submitCreateTaskList}>
-      <div class="form-group">
+      <fieldset>
         <label>
           ${i18nCreateTaskList}
           <input type="text" value="" class="form-control" name="name" placeholder="${i18nTaskListName}" />
@@ -34,6 +34,6 @@ export default function tplMucTaskLists (el, tasklists) {
           ? ''
           : html`<div class="invalid-feedback d-block">${el.create_tasklist_error_message}</div>`
         }
-      </div>
+      </fieldset>
     </form>`
 }