R1:eed10e47c9b5

Conpherence - support device in durable column

Summary:
Ref T7014. This makes it so

- you can't invoke the column from a device
- if you are in desktop size and resize to tablet or phone, the column closes.
- if you resize desktop -> device -> desktop, the column closes at device size and reopens at desktop size
- if you load, then resize device -> desktop the column opens if the user has that preference
- there is a brief flicker when you load on 'device' with the column open preference. it lasts…