Issue #3063339: Rename 'local_service' plugin to 'local_server'

Continues work of 5f321832.

src/Form/FillPdfSettingsForm.php

@@ -267,7 +267,7 @@ class FillPdfSettingsForm extends ConfigFormBase {
       ],
     ];
 
-    $form['local_service'] = [
+    $form['local_server'] = [
       '#type' => 'details',
       '#title' => $this->t('Configure %label', ['%label' => $this->definitions['local_server']['label']]),
       '#open' => TRUE,

tests/src/Functional/PdfParseTest.php

@@ -140,7 +140,7 @@ class PdfParseTest extends FillPdfTestBase {
     // NOTE: Other bugs led me to believe this was the case, but it's kind of a
     // useful method, so I'm just leaving it for now.
     switch ($backend) {
-      case 'local_service':
+      case 'local_server':
       case 'pdftk':
         return 12;
     }