notification client event & user profile page logic

[jasoncheng]

• support invite as a friend click (otype == 'intro'), goto user page
• user page new logic (if API later support user id in notification or user object, that would be great, i can skip step 2.)
• even otype not support yet, still need to mark as seen

1. Notification get user name: https://meld.de/api/friendica/notifications
2. Search User Id by name: https://meld.de/api/users/search?q=andy%20H3 
3. https://meld.de/api/statuses/user_timeline?user_id=77