Random DI improvements (#458)

* Add random DI improvements

Fixing things that were previously missed

* Split InternalFactory into Manager and Helper factories

src/Spout/Writer/Common/Entity/Sheet.php

@@ -29,7 +29,7 @@ class Sheet
     /**
      * @param int $sheetIndex Index of the sheet, based on order in the workbook (zero-based)
      * @param string $associatedWorkbookId ID of the sheet's associated workbook
-     * @param SheetManager $sheetManager
+     * @param SheetManager $sheetManager To manage sheets
      */
     public function __construct($sheetIndex, $associatedWorkbookId, SheetManager $sheetManager)
     {