Enable shifting some services to the host in KVM demo

This issue will track getting in an updated version of the changes to the KVM demo image for CES that enable building with some of the services from the IVI guest shifted into the host.  The original motivation for that was to enable decent audio support since the QEMU audio emulation performance is bad, and virtio-sound is not workable on top of the bits we have available to us in kirkstone ATM.  This then got extended to the databroker and CAN feeder, as the QEMU CAN emulation also seems buggy in QEMU 6.2 (reliably reproducible hangs), and using virto-can proved not feasible.  The databroker changes will also simplify doing builds with the databroker moved out to a gateway box in the future.