Resolve "Veranstaltungsverzeichnis: Einträge ohne Namen sind nicht mehr bearbeitbar"

Closes #3489

Merge request studip/studip!3153

app/views/admin/tree/create.php

 <form class="default" action="<?= $controller->link_for('admin/tree/store', get_class($node), $node->id ?: null) ?>" method="post">
     <section>
         <label>
-            <?= _('Name') ?>
-            <input type="text" name="name"
+            <span class="required">
+                <?= _('Name') ?>
+            </span>
+            <input type="text" name="name" required
                    placeholder="<?= get_class($node) === RangeTreeNode::class ? _('Name des Eintrags (wird bei Zuweisung zu einer Stud.IP-Einrichtung überschrieben)') : _('Name des Eintrags') ?>">
         </label>
     </section>

resources/vue/components/tree/StudipTreeTable.vue

@@ -86,8 +86,13 @@
                         </a>
                     </td>
                     <td>
-                        <studip-icon :shape="child.attributes['has-children'] ? 'folder-full' : 'folder-empty'"
-                                     :size="26"></studip-icon>
+                        <a :href="nodeUrl(child.id, semester !== 'all' ? semester : null)" tabindex="0"
+                           @click.prevent="openNode(child)"
+                           :title="$gettextInterpolate($gettext('Unterebene %{ node } öffnen'),
+                                { node: node.attributes.name }, true)">
+                            <studip-icon :shape="child.attributes['has-children'] ? 'folder-full' : 'folder-empty'"
+                                         :size="26"></studip-icon>
+                        </a>
                     </td>
                     <td>
                         <a :href="nodeUrl(child.id, semester !== 'all' ? semester : null)" tabindex="0"