Add the ability to hide the local video preview in a call

The local video preview widget should be able to be laterally "tucked" under the edge of the call view.

added feature UI/UX labels

assigned to @atraczyk

Not sure if related: But maybe you can also allow to change the size of your own video preview during a call: jami-project#1355 (moved)

Yes, I'll do it in a separate change.

mentioned in commit b38e2167

closed