Display metadata when available (e.g. description, created)

[madprime]

In Data Selfie, a description can be entered -- but this isn't made visible anywhere. Also, activity file updates and uploaded files from projects can have "description" and/or "created" metadata fields. See also Desk case no. 614, and issue #633 (seeing when data was last updated).

We should display this metadata when possible, when listing files on activity pages, profile pages, and research data page.