EZP-23390 - Legacy IO loads whole file to get mime type with FS cluster handler

## EZP-23390_B.diff
diff --git a/kernel/classes/clusterfilehandlers/ezfsfilehandler.php b/kernel/classes/clusterfilehandlers/ezfsfilehandler.php
index 1689b96..25a153c 100644
--- a/kernel/classes/clusterfilehandlers/ezfsfilehandler.php
+++ b/kernel/classes/clusterfilehandlers/ezfsfilehandler.php
@@ -117,7 +117,16 @@ class eZFSFileHandler implements eZClusterFileHandlerInterface
                 eZDebugSetting::writeDebug( 'kernel-clustering', ' clearstatcache called on ' . $this->filePath, __METHOD__ );
             }

-            $this->metaData = file_exists( $this->filePath ) ? stat( $this->filePath ) : false;
+            if ( file_exists( $this->filePath ) )
+            {
+                $this->metaData = stat( $this->filePath );
+                $fileInfo = new finfo( FILEINFO_MIME_TYPE );
+                $this->metaData['datatype'] = $fileInfo->file( $this->filePath );
+            }
+            else
+            {
+                $this->metaData = false;
+            }
             eZDebug::accumulatorStop( 'dbfile' );
         }
     }