perf(export): improve performance of exporter

- use LazyCollectionLoader to prevent memory errors when loading when fetching a big collection
- deactivate time limit for ExportAction (huge collection exports will probably take more than the default 30 seconds to export)

src/Charcoal/Admin/Action/Object/ExportAction.php

@@ -52,6 +52,8 @@ class ExportAction extends AdminAction
      */
     public function run(RequestInterface $request, ResponseInterface $response)
     {
+        set_time_limit(0);
+
         $failMessage = $this->translator()->translation('Failed to export object(s)');
         $errorThrown = strtr($this->translator()->translation('{{ errorMessage }}: {{ errorThrown }}'), [
             '{{ errorMessage }}' => $failMessage

src/Charcoal/Admin/Service/Exporter.php

@@ -12,7 +12,7 @@
 use League\Csv\Writer;
 
 // From 'charcoal-core'
-use Charcoal\Loader\CollectionLoader;
+use Charcoal\Loader\LazyCollectionLoader;
 
 // From 'charcoal-factory'
 use Charcoal\Factory\FactoryInterface;
@@ -185,7 +185,7 @@ public function collection()
             ));
         }
 
-        $collection = new CollectionLoader([
+        $collection = new LazyCollectionLoader([
             'logger'  => $this->logger,
             'factory' => $this->modelFactory()
         ]);