Enhance UX for User Info View (including custom profile fields)

[Ezio-Sarthak]

ZT currently supports a basic version of the user information popup (press i in users list to open), with some trivial details of a user. However, we can improve its user experience further by:

• ~~Displaying human-friendly last active timestamp. e.g., 5 hours ago, instead of the formatted date string.~~
• Displaying additional user information (e.g., favorite editor, status message, Github profile) as per a user's API response.

UPDATE Following brief discussion of this issue, it would seem that date rendering is best handled more uniformly, for which I've opened #1211 - and the web app doesn't currently show the n hours ago for users at the moment in any case? -- neiljp