packaging: split vgpu perception into separate libvgpu-perception0 + -dev packages

- the vmsig package no longer ships the gpu lib; it is a Sensor lib for the control, not the daemon
- vgpu-perception gets SOVERSION; runtime (libvgpu-perception0) and dev (-dev) packages, like the vmie split
- per-component install + a 3-package make deb; fix a stale comment (the windows producer is in-tree)

packaging/deb/vmsig/prerm

@@ -0,0 +1,12 @@
+#!/bin/sh
+set -e
+case "$1" in
+remove|deconfigure)
+    if [ -d /run/systemd/system ]; then
+        systemctl disable --now vmsigd.service || true
+    fi
+    ;;
+upgrade|failed-upgrade)
+    ;;
+esac
+exit 0