* Convert tabbedview to functional component

The 'Tab' is still a class, so now it's a functional component that
has a supporting class, which is maybe a bit... jarring, but I think
is actually perfectly logical.

* put comment back

* Fix bad tab ID behaviour

* Make TabbedView a controlled component

This does mean the logic of keeping what tab is active is now in each
container component, but for a functional component, this is a single
line. It makes TabbedView simpler and the container components always
know exactly what tab is being displayed rather than having to effectively
keep the state separately themselves if they wanted it.

Based on matrix-org/matrix-react-sdk#12478

* Fix some types & unused prop

* Remove weird behaviour of using first tab is active isn't valid

* Don't pass initialTabID here now it no longer has the prop

* Fix test

* bleh... id, not icon

* Change to sub-components

and use contitional call syntax

* Comments

* Fix element IDs

* Fix merge

* Test DesktopCapturerSourcePicker

to make sonarcloud the right colour

* Use custom hook for the fllback tab behaviour