feat(node): package Ubuntu desktop setup and trusted access

apps/node-agent/packaging/prerm

@@ -0,0 +1,21 @@
+#!/bin/sh
+set -eu
+case "$1" in
+  remove|deconfigure)
+    mc_node_ssh_snippet=/etc/ssh/sshd_config.d/60-mission-core-node.conf
+    if [ -e "$mc_node_ssh_snippet" ]; then
+      if cmp -s /usr/share/mission-core-node/60-mission-core-node.conf "$mc_node_ssh_snippet"; then
+        rm "$mc_node_ssh_snippet"
+      else
+        mc_node_saved_snippet=$(mktemp /etc/ssh/sshd_config.d/mission-core-node-removed.XXXXXX)
+        mv "$mc_node_ssh_snippet" "$mc_node_saved_snippet"
+      fi
+    fi
+    if [ -d /run/systemd/system ]; then
+      /usr/sbin/sshd -t
+      systemctl try-reload-or-restart ssh.service
+      systemctl stop mission-core-node.service
+      systemctl disable mission-core-node.service
+    fi
+    ;;
+esac