Added avatar img and username to notifications

Added robovatar img, and was lazy to add another column to db for the commentAuthor.username so used regex instead to extract first word out from body text (but might break if I change the phrasing structure of the body text in future).

{{ notif.body.replace(/ .*/, '') }}

Ref: https://stackoverflow.com/a/46999443

UPDATE: the regex did break the notif text body. Text was rendering weirdly in the username part of the notif. Changed to using a split() function.

{{ notif.body.split(' ')[0] }}

Ref: https://stackoverflow.com/a/19503397