Notifications panel crashes on unsupported notification

Related issue: pleroma#1559 (closed)

pleroma!2354 (merged) adds new notification type, follow_request. It has exactly the same contents as follow despite the type field.

It's expected that unsupported / unrecognized notifications are to be ignored or, better, attempted to be generically displayed (need to discuss that possibilty).

However, unsupported notification makes Notifications panel display "Error fetching updates" error, and if user reloads the page then Notifications would only display the error and not show any notifications.

See the video:

https://drive.google.com/file/d/1stZDbjuHfxpFTr9KOuNn9tx8715z5Cqn/view?usp=sharing

P.S. If trying to reproduce with pleroma!2354 (merged), see the description on enabling follow_request notifications.