Earpiece switcher and overlay (#3347)

* Add a global control for toggling earpiece mode

This will be used by Element X to show an earpiece toggle button in the header.

* Add an earpiece overlay


* Fix header
The header needs to be passed forward as a string to some components and as a bool (hideHeader) to others.
Also use a enum instead of string options.

* fix top clipping with header


* hide app bar in pip

* revert android overlay app_bar

* Modernize AppBarContext

* Style header icon color as desired and switch earpice/speaker icon

* fix initial selection when using controlled media

* Add "Back to video" button

* fix tests

* remove dead code

* add snapshot test

* fix back to video button

* Request capability to learn the room name

We now need the room name in order to implement the mobile (widget-based) designs with the app bar.

* Test the CallViewModel output switcher directly

---------

Co-authored-by: Timo <toger5@hotmail.de>

src/room/InCallView.module.css

@@ -18,7 +18,7 @@ Please see LICENSE in the repository root for full details.
   position: sticky;
   flex-shrink: 0;
   inset-block-start: 0;
-  z-index: 1;
+  z-index: var(--call-view-header-footer-layer);
   background: linear-gradient(
     0deg,
     rgba(0, 0, 0, 0) 0%,
@@ -34,7 +34,7 @@ Please see LICENSE in the repository root for full details.
 .footer {
   position: sticky;
   inset-block-end: 0;
-  z-index: 1;
+  z-index: var(--call-view-header-footer-layer);
   display: grid;
   grid-template-columns:
     minmax(0, var(--inline-content-inset))