Allow stopping/restarting cal-services.target to affect services

webservice/systemd/cal-job-monitor.service

 [Unit]
 Description=XFEL offline calibration Slurm job monitor
+PartOf=cal-services.target
 
 [Service]
 Type=exec

webservice/systemd/cal-overview-server.service

 [Unit]
 Description=XFEL offline calibration status web page
+PartOf=cal-services.target
 
 [Service]
 Type=exec

webservice/systemd/cal-webservice.service

 [Unit]
 Description=XFEL offline calibration ZMQ service
+PartOf=cal-services.target
 
 [Service]
 Type=exec