move requests to backend (#18)

source/view/events-list-group-not-found.php

@@ -0,0 +1,11 @@
+<?php
+namespace MobilizonConnector;
+
+// Exit if this file is called directly.
+if (!defined('ABSPATH')) {
+  exit;
+}
+?>
+<div class="<?php echo esc_attr($classNamePrefix); ?>_events-list">
+  <?php echo esc_html(sprintf(__('The group "%s" could not be found!', 'connector-mobilizon'), $groupName)); ?>
+</div>