browser: Remote Control implementation: - Add `cbor-x` JS dependency. - In "Call" page, a Remote Control session can now be started. This is done by clicking on a search item 3 dots menu. Libervia Web will act as a controlling device. The call box is then adapted, and mouse/wheel and keyboard events are sent to remote, touch events are converted to mouse one. - Some Brython 3.12* related changes. rel 436