The pipewire loop now runs without interruption in a second thread and communicates with
the GTK thread via a channel in each direction, instead of checking for events once a second and using callbacks.
This allows changes to appear instantly in the view, instead of having to wait.
The controller still determines the ports media type, but instead of coloring
the port itself, the media type is passed to the constructor, which then colors the port.
struct PipewireConnection is now decoupled from any other components, another component (the controller)
can receive updates by registering a callback.
struct PipewireState has been refactored to a struct Controller.
It still keeps state and manages the view, but now also actively requests updates from the pipewire connection via callback.
