Reject form.
This method gets call by tmgmt_translation_review_form_reject_confirm and allows the translator to add aditional form elements in order to collect data needed for the reject prozess.
$form: The form array containing a confirm form. $form['item'] holds the job item to which the to be rejected data item belongs to. $form['item'] holds key of the to be rejected data item as an array of keys of a nested array hierarchy.
$form_state: The form state.
The resulting form array.
public function rejectForm(array $form, FormStateInterface $form_state);