Translation: add a module-aware translation helper

With this fix $this->translate works in our view scripts

refs #6338

library/Icinga/Web/Controller/ActionController.php

@@ -128,6 +128,9 @@ class ActionController extends Zend_Controller_Action
             $this->windowId = $this->_request->getHeader('X-Icinga-WindowId', null);
         }
 
+        $module = $request->getModuleName();
+        $this->view->translationDomain = $module === 'default' ? 'icinga' : $module;
+
         if ($this->requiresConfig() === false) {
             if ($this->requiresLogin() === false) {
                 $this->view->tabs = new Tabs();

library/Icinga/Web/View.php

@@ -31,6 +31,7 @@
 namespace Icinga\Web;
 
 use Icinga\Exception\ProgrammingError;
+use Icinga\Util\Translator;
 use Zend_View_Abstract;
 use Closure;
 
@@ -154,6 +155,11 @@ class View extends Zend_View_Abstract
         );
     }
 
+    public function translate($text)
+    {
+        return Translator::translate($text, $this->translationDomain);
+    }
+
     /**
      * Load helpers
      */