feat(Style): add van-safe-area-bottom util class (#9205)

* feat(Style): add van-safe-area-bottom class

* chore: update test cases

src/action-sheet/test/__snapshots__/index.spec.ts.snap

@@ -19,7 +19,7 @@ exports[`should render default slot correctly 1`] = `
   </div>
 </transition-stub>
 <transition-stub>
-  <div class="van-popup van-popup--round van-popup--bottom van-popup--safe-area-inset-bottom van-action-sheet">
+  <div class="van-popup van-popup--round van-popup--bottom van-safe-area-bottom van-action-sheet">
     <div class="van-action-sheet__header">
       Title
       <i class="van-badge__wrapper van-icon van-icon-cross van-action-sheet__close">

src/action-sheet/test/index.spec.ts

@@ -248,13 +248,13 @@ test('should allow to control safe-area with safe-area-inset-bottom prop', async
   });
 
   expect(wrapper.find('.van-action-sheet').classes()).toContain(
-    'van-popup--safe-area-inset-bottom'
+    'van-safe-area-bottom'
   );
 
   await wrapper.setProps({
     safeAreaInsetBottom: false,
   });
   expect(wrapper.find('.van-action-sheet').classes()).not.toContain(
-    'van-popup--safe-area-inset-bottom'
+    'van-safe-area-bottom'
   );
 });