UnsignedData does not hold 2 fields from v1.16

[hikingc]

From spec:
[Changed in v1.16] The m.room.create event is now required in the following places:

invite_state and knock_state on /sync responses.
On m.room.member events, the invite_room_state and knock_room_state under unsigned on the event.

[hikingc]

This means there is more than 1 "type" of UnsignedData