Include Contact type messages / Vcards in gallery and making it possible to search for them in chat

[ian]

Related (this would enable you to search for vcf or .vcf):

Also search for text in attachment filename and XDC manifest name

When a user is searching for messages that match a given keyword, also return messages with attachments whose remote name matches (i.e., not its hash). Also include webxdc apps whose manifest name matches, because that is also displayed in the timeline as if it was part of the message.