Debian/buster startup sequencer

Packing needed to support the startup sequencer in !185 (closed). Adds advligorts-startup-sequencer package and makes advligorts-fe depend on it.

Installs the python program, several needed shell scripts, and a couple of systemd units.

debian/advligorts-startup-sequencer.install

+usr/lib/startup_sequencer/*
+usr/bin/startup_sequencer
+etc/dbus-1/system.d/edu.caltech.cds.Sequencer.conf
+lib/systemd/system/rts-daq-ethernet.service
+lib/systemd/system/rts-startup_sequencer.service
\ No newline at end of file