Picture-in-picture stops when switching view layout

[taoeffect]

When you switch from the grid/tile view to focusing on one window (and vice versa), the picture-in-picture feed stops. You have to close the PIP window and re-open it for it to continue the video feed.

EDIT: it would also be nice to have other improvements related to this:

• When someone turns off their camera, to have the PIP show their first letter
• When there are multiple people in the call, to split the viewport halfway (e.g. when there's 3 people on the call, showing the 2 you're chatting with, and when there's more, showing a 2x2 grid; see again Whereby's handling of this)