default-routes: save and restore iec958Codecs
Similar to the volume and latencyOffset we need parse, save and restore the configured iec958Codecs on the node.
Pavucontrol will use the device-restore extension to set the configured iec958Codecs on the Node/Route. This will make the node enumerate audio/iec958 formats, which can be matched against streams that can provide this format to configure passthrough.
Fixes #64 (closed)