title: Formik FieldArray after upating field (which is used to sort array) array sorts but focus is incorrect
body: <p>I'm using Formik's FieldArray to add/remove extra fields of objects from a form. In the objects array, there is a field called position that the array is sorted by when rendering e.g.:</p>
  <pre><code>&lt;FieldArray name=&quot;my_values&quot;&gt;
    {({ push, remove }) =&gt; (
      values.sort((a, b) =&gt; a.position - b.position).map(value = etc...
  </code></pre>
  <p>For example, if I have two objects:</p>
  <pre><code>{ name: 'Jane', position: 2 }
  { name: 'John', position: 1 }
  </code></pre>
  <p>John will appear first in the form with his name and position field and Jane after. If I update John's position to 3 in the form, Formik will re-render the Form and the Jane and their object's fields will appear first and John after, which is the desired functionality.</p>
  <p>The issue is small but I've been stumped at how to solve:</p>
  <p><strong>After sorting again after this position change, I'm focused on the input that's in the first position, which is Jane's position. As I've just edited John's position, I would expect as the user to still be focussed on John's position that now appears below Jane in the FieldArray</strong></p>
  <p>Any ideas on how to &quot;follow&quot; and keep focussed on this field after the array has been sorted?</p>