[iOS] Timetable Grid: Double Field events

[charles-b-stb]

There is an even type "RoomIJ" whose usage and display type is unclear.

1. Find out if we actually need to implement this for timetable
2. If we need to implement it, do so

[charles-b-stb]

Insofar as I can tell, the two event fields only related to workshop day, which is no longer included.

The only part that remains is events that the spec intends to stretch over multiple slots (items in room J/Jellyfish like lunch or opening session). These events are always in roomJ but also there will probably also be events in roomJ that run parallel to other events (currently there are none of these in the data)

Proposal: If there is a Jellyfish/roomJ event and no other events going on, stretch that event to fit the whole field?

This seems to fit the proposed design without significant data changes.