Button values and messages during field creation workflow have changed

The field creation workflow now creates and saves the field config and field storage config entities at the last step of the process, instead of the first. To improve the user experience, the UI is now using "Continue" instead of "Save and continue" and "Save field settings". Messages that said "Your settings have been saved" are not displayed until the field is actually saved after the final step. These changes may impact existing test coverage, or other code that is relying on the texts used in the form.

Before:

$page->findButton('Save field settings')->click();
$assert_session->pageTextContains("Updated field $label field settings.");

After:

$page->findButton('Continue')->click();

In order to enhance the maintainability and execution speed of Drupal modules' test suites, module developers should refrain from relying on the user interface for adding fields during testing, unless the test is specifically intended to test the Field UI integration. Instead, developers are encouraged to utilize Drupal's API to programmatically create and manage fields in test that require those fields but that don't need to test the Field UI.

Following code could be used for creating field storage config and field config:

$field_storage = FieldStorageConfig::create([
  'field_name' => 'field_test',
  'entity_type' => 'test_entity',
  'type' => 'test_field_type',
]);
$field_storage->save();

$field = FieldConfig::create([
  'field_name' => 'field_test',
  'entity_type' => 'test_entity',
  'bundle' => 'test_content',
  'label' => 'Test',
]);
$field->save();