feat(ShareSheet): add cancel slot (#8335)

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

@@ -1,5 +1,13 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
+exports[`should render cancel slot correctly 1`] = `
+<button type="button"
+        class="van-share-sheet__cancel"
+>
+  Custom Cancel
+</button>
+`;
+
 exports[`should render cancel text when using cancel-text prop 1`] = `
 <button type="button"
         class="van-share-sheet__cancel"

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

@@ -104,3 +104,16 @@ test('should emit click-overlay event when overlay is clicked', async () => {
   expect(onClickOverlay).toHaveBeenCalledTimes(1);
   expect(wrapper.emitted('update:show')![0]).toEqual([false]);
 });
+
+test('should render cancel slot correctly', async () => {
+  const wrapper = mount(ShareSheet, {
+    props: {
+      show: true,
+    },
+    slots: {
+      cancel: () => 'Custom Cancel',
+    },
+  });
+
+  expect(wrapper.find('.van-share-sheet__cancel').html()).toMatchSnapshot();
+});