CrossSigning / Update Shield Logic for DM

[BillCarsonFr]

#see element-hq/element-web#12214

There are some cases where this doesn't happen today, e.g. if you have not verified one of your own devices, all rooms would go red (even large public rooms where you have no intention verifying users).

To make the experience more straightforward, we decided after chatting with @dbkr and @nadonomy to add the additional check that green / red states are only shown if you have verified at least one user in the room. If you haven't, the room is black.

Summary doc on shields: https://docs.google.com/document/d/1RFUN0YRrOs8QZwiblaUbs4wWR0BjA0hBJ27rKJ57Zvk/edit

[manuroe]

Kamino cloned this issue to vector-im/riot-ios

[BillCarsonFr]

DM

If you see a shield on a DM, you cognitively map that decoration to the other person only (I don't care about rooms, I just care about chatting with Alice. If I see a green tick on a DM with Alice, it's indicative of her and not me.)
So, it makes sense to abstract you away from a 1:1 DM

Group DM

From there, the same holds true of groups