[TASK] Use calendarize icons in TCA

In TCA, the corresponding icons from Icons.php will be used
for each plugin. This way, the calendarize icons are displayed
instead of the general plugin icon in the backend.

Resolves: #869

Author: sypets

Configuration/TCA/Overrides/tt_content.php

@@ -28,11 +28,12 @@
 );
 
 foreach ($pluginNameAndGroup as $pluginName => $group) {
+    $pluginNameLowercase = strtolower($pluginName);
     $pluginSignature = TYPO3\CMS\Extbase\Utility\ExtensionUtility::registerPlugin(
         'calendarize',
         $pluginName,
-        $ll . 'mode.' . strtolower($pluginName),
-        null,
+        $ll . 'mode.' . $pluginNameLowercase,
+        'ext-calendarize-wizard-icon-' . $pluginNameLowercase,
         $group,
     );
     // Disable the display of layout and select_key fields for the plugin