Preprints: Attachments don't attach to emails (eg to Preprint Owner)

Describe the bug
When using the "Contact Owner" field to email the submitting author of a Repository Item, attachments don't actually attach

Janeway version
Version: 1.5.6

To Reproduce
Steps to reproduce the behavior:

1. Go to Repository Manager and open the manager view of a Repository Item
2. Click "Contact Owner" to contact the submitting author for the item
3. Fill the form with required details, then attach an item. CC yourself so you can receive the email
4. Open the email and note the lack of attachment
5. View the log and note the lack of information regarding the attachment

Expected behavior
The attached file would be attached to the email

A record of the file would be noted in the email log. e.g. Attachment: file.pdf

bonus: the attachment would be stored in Janeway log

Screenshots

Previously: File attachment does not get delivered when emailing an author directly, entire message missing from logs #3873

Note: Attachments properly attach in the email for accepting/rejecting preprints. However, record of the attachment is not recorded in the email log, nor is a copy of the attachment stored.