[backport core/1.42] fix(load3d): fix squashed controls in 3D inspector side panel (#10871)

Backport of #10768 to `core/1.42`

Automatically created by backport workflow.

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-10871-backport-core-1-42-fix-load3d-fix-squashed-controls-in-3D-inspector-side-panel-33a6d73d365081048cd5f9ebbdc57b63)
by [Unito](https://www.unito.io)

Co-authored-by: Kelly Yang <124ykl@gmail.com>

src/components/load3d/controls/viewer/ViewerModelControls.vue

@@ -1,6 +1,6 @@
 <template>
   <div class="space-y-4">
-    <div>
+    <div class="flex flex-col gap-2">
       <label>{{ $t('load3d.upDirection') }}</label>
       <Select
         v-model="upDirection"
@@ -10,7 +10,7 @@
       />
     </div>
 
-    <div v-if="!hideMaterialMode">
+    <div v-if="!hideMaterialMode" class="flex flex-col gap-2">
       <label>{{ $t('load3d.materialMode') }}</label>
       <Select
         v-model="materialMode"