unify user popovers into a separate component

src/components/user_popover/user_popover.js

@@ -0,0 +1,14 @@
+import { defineAsyncComponent } from 'vue'
+
+const UserPopover = {
+  name: 'UserPopover',
+  props: [
+    'userId', 'overlayCenters', 'disabled'
+  ],
+  components: {
+    UserCard: defineAsyncComponent(() => import('../user_card/user_card.vue')),
+    Popover: defineAsyncComponent(() => import('../popover/popover.vue'))
+  }
+}
+
+export default UserPopover