Pull request #726: - client: 1954 Make menu items position stable

- client: 1954 Make menu items position stable
Close #1954

Squashed commit of the following:

commit 24bc6faa1e45cef79e3ba83ad5d595c305e0c816
Merge: a4b07aae d3f5b407
Author: ArtemBaskal <a.baskal@adguard.com>
Date:   Thu Aug 13 10:51:47 2020 +0300

    Merge branch 'master' into fix/1954

commit a4b07aae4b3b56d60cc95f669e6c179659d904ce
Author: ArtemBaskal <a.baskal@adguard.com>
Date:   Wed Aug 5 15:20:26 2020 +0300

    Review changes

commit 250cdc9b10f93664ed2c1f53d57295dba78e6a99
Merge: 32003f19 39f2d5c4
Author: ArtemBaskal <a.baskal@adguard.com>
Date:   Wed Aug 5 15:18:40 2020 +0300

    Merge branch 'master' into fix/1954

commit 32003f19c6e2dda056fa6ae51f6721ea350016d1
Author: ArtemBaskal <a.baskal@adguard.com>
Date:   Mon Aug 3 13:36:23 2020 +0300

    - client: 1954 Make menu items position stable

client/src/helpers/helpers.js

@@ -672,3 +672,12 @@ export const processContent = (content) => (Array.isArray(content)
     ? content.filter(([, value]) => value).reduce((acc, val) => acc.concat(val), [])
     : content
 );
+
+/**
+ * @param object {object}
+ * @param sortKey {string}
+ * @returns {string[]}
+ */
+export const getObjectKeysSorted = (object, sortKey) => Object.entries(object)
+    .sort(([, { [sortKey]: order1 }], [, { [sortKey]: order2 }]) => order1 - order2)
+    .map(([key]) => key);