[MlMt] Add more specific buttons for attachment actions

[Martin Guddat]

Is there a way to add more buttons to attachments in mails?

Currently there is „Quick Look“ and „Save“. I would love to have 
„Open Attachment“ and „Save NAME …“

In a perfect world it would be possible to change buttons depending on 
subject, attachment type etc. But fixes buttons I can configure would be 
great. Any help is appreciated, I have not found anything on this in de 
documentation.

Thanks
Martin