Add a default formatter for field type Zone

Added a default formatter

After applying this patch I am not getting more warning messages, and field settings for allowed number of values is still set to 1 with no options to configure. But when I populate fields I can add multiple number of values, not just one. I did rebuild cache after applying the patch.

  *   default_widget = "address_zone_default",
+ *   default_formatter = "zone_default",

The widget is address_zone_default, the field type is address zone, the formatter can't be zone_default, needs to also be prefixed with address_

+  /**
+   * Constructs an AddressDefaultFormatter object.
+   *

Wrong class name in docblock.

+  /**
+   * Generate the output appropriate for one field item.
+   *
+   * @param \Drupal\Core\Field\FieldItemInterface $item
+   *   One field item.
+   * @param string $langcode
+   *   The language that should be used to render the field.
+   *
+   * @return array
+   *   A renderable array.
+   */
+  protected function viewValue(FieldItemInterface $item, $langcode) {

Our other formatters call this method viewElement, let's do the same here. Also, let's pass a Zone object ($item->value).

+      if (!empty($administrative_area = $territory->getAdministrativeArea())) {

You don't need the !empty.

+        $element[$key]['dlocality'] = [
+          '#type' => 'html_tag',
+          '#tag' => 'span',
+          '#attributes' => ['class' => [$address_format->getDependentLocalityType()]],
+          '#value' => $dependent_locality,
+        ];

We shouldn't abbreviate element names. "dependent_locality", not "dlocality",
Also, dependent_locality should come after locality, not before.

+          '#type' => 'html_tag',
+          '#tag' => 'span',

Let's use the "item" type and give each element an appropriate label.

Also, we're not printing the zone label.

Here's an updated patch.

Let's proceed. We can open follow-up issues for any other zone bugs.

Thanks, everyone.