proxy: add global_id property

lib/wp/proxy-node.c

lib/wp/proxy-node.h

lib/wp/proxy-port.c

lib/wp/proxy-port.h

lib/wp/proxy.c

lib/wp/proxy.h

modules/module-pipewire.c

modules/module-pipewire/simple-endpoint.c

modules/module-pw-alsa-udev.c