Builds a conversion form to add extra settings to the conversion.
This method is responsible for building the conversion form for each Paragraph so the user can set special attributes and properties.
\Drupal\paragraphs\ParagraphInterface $paragraph: The paragraph.
array $form: An associative array containing the initial structure of the plugin form.
\Drupal\Core\Form\FormStateInterface $form_state: The current state of the form.
array The fields build array that the plugin creates.
public function buildConversionForm(ParagraphInterface $paragraph, array &$form, FormStateInterface $form_state);