No mail attachments when Opt-In is active and DB saving is disabled

[599media]

In powermail 12.5 (actually since https://github.com/in2code-de/powermail/commit/b01275d01f6685ab72c6718ff8b5c01a9baf7ff3) the sent mail does not contain attachments when opt-in is active and db saving is disabled.

The problem is, that the actual mail is deleted before mail had been sent (see https://github.com/in2code-de/powermail/blob/typo3-v12/Classes/Controller/FormController.php#L460-L464). It's no problem for the mail content directly attached to the $mail object, but the attachments for the mail are received by fillFilesFromExistingMail function of the UploadService (see https://github.com/in2code-de/powermail/blob/typo3-v12/Classes/Domain/Service/UploadService.php#L222-L251). Since the mail does not exist anymore, the repository cannot return the mail in https://github.com/in2code-de/powermail/blob/typo3-v12/Classes/Domain/Service/UploadService.php#L228.

Maybe the mail deletion should be handled in the createAction after the mail had been sent after opt-in.