Fix DeepL free tier API not usable after unchecking DeepL pro checkbox

Fix DeepL free tier API not usable after unchecking DeepL pro checkbox Rename variable to better reflect the "true" means use pro API mode. Add update hook and bool conversion for new variable name to fix existing installs having "0" in the DB.

src/Form/AutoTranslatorSettingsForm.php

@@ -289,11 +289,11 @@ class AutoTranslatorSettingsForm extends ConfigFormBase {
       ],
     ];
 
-    $form['configuration_nodes']['api_settings']['auto_translation_api_deepl_mode'] = [
+    $form['configuration_nodes']['api_settings']['auto_translation_api_deepl_pro_mode'] = [
       '#type' => 'checkbox',
       '#title' => $this->t('Use DeepL Pro API'),
       '#description' => $this->t('If checked, the DeepL Pro API will be used. If unchecked, the free version of DeepL will be used.'),
-      '#default_value' => $config->get('auto_translation_api_deepl_mode'),
+      '#default_value' => (bool) $config->get('auto_translation_api_deepl_pro_mode'),
       '#states' => [
         'visible' => [
           ':input[name="auto_translation_provider"]' => ['value' => 'deepl'],
@@ -367,7 +367,7 @@ class AutoTranslatorSettingsForm extends ConfigFormBase {
       ->set('auto_translation_content_types', $form_state->getValue('auto_translation_content_types'))
       ->set('auto_translation_api_enabled', (bool) $form_state->getValue('auto_translation_api_enabled'))
       ->set('auto_translation_api_key', $encryptedApiKey)
-      ->set('auto_translation_api_deepl_mode', (bool) $form_state->getValue('auto_translation_api_deepl_mode'))
+      ->set('auto_translation_api_deepl_pro_mode', (bool) $form_state->getValue('auto_translation_api_deepl_pro_mode'))
       ->set('auto_translation_excluded_fields', $excludedFields)
       ->set('auto_translation_provider', $provider)
       ->set('auto_translation_bulk_publish', Html::escape($form_state->getValue('auto_translation_bulk_publish')))