TinyMCE wiki attachments should open the details/preview of files instead of direct download

When inserting attachments in the old CKEditor, those links included a file icon (e.g. red PDF sheed for PDFs) and a link to the file preview. So if the user clicks on this link, he see the file preview (if avaliable, for e.g. images) and the sidebar with meta information like file owner, description, tags and others.

But since we're switched to the latest TinyMCE, the attachment insertion changed: The file type icon is gone and the link doesn't target the view file link as described above. Instead, it inserts a direct download link.

This is suboptimal since users were forced to download all attachments, even when the files app could display it in the browser like on images. It's even worser on office documents because the preview page also contains the "Edit on Desktop" button. Because of the direct link, the users haven't any change to press this button because they just get a direct file download.

To fix this, TinyMCE should also link attachments to the preview page instead of a direct link for downloading.