Add simple store with sidebar toggle action

[MAILPOET-2450]

assets/js/src/form_editor/components/header.jsx

@@ -1,22 +1,31 @@
 import React from 'react';
 import { IconButton } from '@wordpress/components';
+import { useDispatch, useSelect } from '@wordpress/data';
 
-export default () => (
-  <div className="edit-post-header">
-    <div className="edit-post-header-toolbar" />
-    <div className="edit-post-header__settings">
-      <button
-        type="button"
-        className="components-button editor-post-publish-panel__toggle is-button is-primary"
-      >
-        Save
-      </button>
-      <IconButton
-        icon="admin-generic"
-        label="Settings"
-        onClick={() => null}
-        isToggled
-      />
+export default () => {
+  const sidebarOpened = useSelect(
+    (select) => select('mailpoet-form-editor').getSidebarOpened(),
+    []
+  );
+  const { toggleSidebar } = useDispatch('mailpoet-form-editor');
+  return (
+    <div className="edit-post-header">
+      <div className="edit-post-header-toolbar" />
+      <div className="edit-post-header__settings">
+        <button
+          type="button"
+          className="components-button editor-post-publish-panel__toggle is-button is-primary"
+        >
+          Save
+        </button>
+        <IconButton
+          icon="admin-generic"
+          label="Settings"
+          labelPosition="down"
+          onClick={() => toggleSidebar(!sidebarOpened)}
+          isToggled={sidebarOpened}
+        />
+      </div>
     </div>
-  </div>
-);
+  );
+};