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.
This updates all crates to their newest release.
For pipewire-rs, this includes bumping the version to 0.3, which means this comment has to fix a few breaking changes, but nothing big.
0.3 also lets us create and delete remote objects, which will be needed for link creation and deletion.
