quagga: Fixup startup to allow consistency between sysV and systemd

quagga: Fixup startup to allow consistency between sysV and systemd

We want the ability to start up quagga in a varied set of
environments.  This needs to be done in SysV and systemd
startups.  As such refactor the code to allow us to
allow end users to easily switch between the two

sysV:
edit the /etc/quagga/daemons file
service quagga [start|stop|reload|restart]

Systemd:
edit the /etc/quagga/daemons file
systemctl [start|stop|reload|restart] quagga

Ticket: CM-10634
Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>
Reviewed-by: Daniel Walton <dwalton@cumulusnetworks.com>