Deprecate vue mount component helper

https://gitlab.com/groups/gitlab-org/-/epics/2445

spec/frontend/helpers/vue_mount_component_helper.js

 import Vue from 'vue';
 
+/**
+ * Deprecated. Please do not use.
+ * Please see https://gitlab.com/groups/gitlab-org/-/epics/2445
+ */
 const mountComponent = (Component, props = {}, el = null) =>
   new Component({
     propsData: props,
   }).$mount(el);
 
+/**
+ * Deprecated. Please do not use.
+ * Please see https://gitlab.com/groups/gitlab-org/-/epics/2445
+ */
 export const createComponentWithStore = (Component, store, propsData = {}) =>
   new Component({
     store,
     propsData,
   });
 
+/**
+ * Deprecated. Please do not use.
+ * Please see https://gitlab.com/groups/gitlab-org/-/epics/2445
+ */
 export const mountComponentWithStore = (Component, { el, props, store }) =>
   new Component({
     store,
     propsData: props || {},
   }).$mount(el);
 
+/**
+ * Deprecated. Please do not use.
+ * Please see https://gitlab.com/groups/gitlab-org/-/epics/2445
+ */
 export const mountComponentWithSlots = (Component, { props, slots }) => {
   const component = new Component({
     propsData: props || {},
@@ -30,9 +46,18 @@ export const mountComponentWithSlots = (Component, { props, slots }) => {
 /**
  * Mount a component with the given render method.
  *
+ * -----------------------------
+ * Deprecated. Please do not use.
+ * Please see https://gitlab.com/groups/gitlab-org/-/epics/2445
+ * -----------------------------
+ *
  * This helps with inserting slots that need to be compiled.
  */
 export const mountComponentWithRender = (render, el = null) =>
   mountComponent(Vue.extend({ render }), {}, el);
 
+/**
+ * Deprecated. Please do not use.
+ * Please see https://gitlab.com/groups/gitlab-org/-/epics/2445
+ */
 export default mountComponent;

spec/javascripts/helpers/vue_mount_component_helper.js

-import Vue from 'vue';
-
-const mountComponent = (Component, props = {}, el = null) =>
-  new Component({
-    propsData: props,
-  }).$mount(el);
-
-export const createComponentWithStore = (Component, store, propsData = {}) =>
-  new Component({
-    store,
-    propsData,
-  });
-
-export const mountComponentWithStore = (Component, { el, props, store }) =>
-  new Component({
-    store,
-    propsData: props || {},
-  }).$mount(el);
-
-export const mountComponentWithSlots = (Component, { props, slots }) => {
-  const component = new Component({
-    propsData: props || {},
-  });
-
-  component.$slots = slots;
-
-  return component.$mount();
-};
-
-/**
- * Mount a component with the given render method.
- *
- * This helps with inserting slots that need to be compiled.
- */
-export const mountComponentWithRender = (render, el = null) =>
-  mountComponent(Vue.extend({ render }), {}, el);
-
-export default mountComponent;
+export { default } from '../../frontend/helpers/vue_mount_component_helper';
+export * from '../../frontend/helpers/vue_mount_component_helper';