feat(@vant/use): add onMountedOrActivated

packages/vant-use/src/onMountedOrActivated/index.ts

@@ -0,0 +1,18 @@
+import { nextTick, onMounted, onActivated } from 'vue';
+
+export function onMountedOrActivated(hook: () => any) {
+  let mounted: boolean;
+
+  onMounted(() => {
+    hook();
+    nextTick(() => {
+      mounted = true;
+    });
+  });
+
+  onActivated(() => {
+    if (mounted) {
+      hook();
+    }
+  });
+}