Implement BLE MIDI node, providing an input and output port. MIDI data
received is normalized and produced on output port. Data from input
port is converted to BLE MIDI and sent to the device.
Event timestamps come from device clock, whose offset to wall clock we
determine by correlating packet reception times with their timestamps.
The jitter in packet reception is likely much larger than device clock
error, so we average over that.
For backward compatibility with old Wireplumber releases, support the
old api.bluez5.a2dp.sink/source names, and use them in object events
instead of the media.sink/source names.
Remove the monitor API, we can use the device API for it. Make sure
we support creating devices (like alsa) from another device (udev).
Use new object.id to store the object id in the object properties. Use
the port.id/node.id etc to make relations to other objects.
