Breaking: #35 - Extract writing document to FileWriterService 

See Issue 135

Description 

To enable the PDF content to be written using a separate file name, writing the rendered content should be moved to a separate service.

Your own service can then be integrated via dependency injection.

Affected Installations 

All installations which overwrite \Extcode\CartPdf\Service\PdfService::createPdf and \Extcode\CartPdf\Service\PdfService::renderPdf are affected. These methods were removed. The functionality was moved to \Extcode\CartPdf\Service\PdfService::renderDocument and return the pdf content as string. Saving the file was handed over to the new \Extcode\CartPdf\Service\FileWriterService::writeContentToFile.

Migration 

Move the logic to an own implementation of the \Extcode\CartPdf\Service\FileWriterServiceInterface and inject this own service to the \Extcode\CartPdf\EventListener\Order\Finish\DocumentRenderer.