[Email] Add attachment functionality

[CamilleBeau]

Brief summary of changes

This PR adds to the Email.class.inc library file to be able to add attachments to emails sent by LORIS.

This is done by detecting whether an array of attachments was added, and if so, changing the Content-Type to multi-part and adding each attachment individually. If no attachments are passed as an argument, then the Email class continues as it did before.

• Have you updated related documentation?

Testing instructions (if applicable)

1. Add a 9th argument to an Email::send function somewhere in LORIS with a full filepath passed through
2. Have the email sent to your own address, and make sure that the attachment is added to the sent email properly
3. Try sending an email like normal without an attachment, and make sure that that works as usual.

Link(s) to related issue(s)

• Resolves # (Reference the issue this fixes, if any.)

[ridz1208]

@CamilleBeau FYI here is how I had implemented it. I really don't recall why I did moved away from the Email class but I rememebr trying and giving up at a certain point.

            //email
            $config =& NDB_Config::singleton();
            $from = ($config->getSetting('mail'))['From'];
            
            $email = new PHPMailer();
            $email->SetFrom($from);
            $email->Subject = "THIS IS THE SUBJECT LINE";
            $email->Body = "THIS IS THE BODY";
            $recipientEmail = $config->getSetting("mailto");
            $email->AddAddress($recipientEmail);
            $email->AddAddress("rida.abou-haidar@mcin.ca");
            $email->AddAttachment( $EOS_path , $EOS_file);
            $email->AddAttachment( $o_path , $o_file);
            $email->Send();