Article UI Attachment upload is broken #1136
Description
In Argu Articles there is a button that allows users to upload files as attachments to posts. This button relied on default logic that no longer exists. Uploading files used to automatically create an attachment property on the parent but this was removed since it doesn't make sense in most usecases.
To fix this we can just add this logic back to the Article page specifically.
I noticed ArticlePage is using UploadForm, this component is not used by anything else anymore and should probably be renamed/moved to make it article specific.