Draft: feat(api,webapp): show viewer protocol when connected

• Needs setting the monitoring domain or domain to reach monitor host
• Last viewer is not cleared in datatables (no data is sent...). There is desktop_viewer_clear event but needs work.
• Extrange behaviour detecting viewers when more than one is connected at the same time. Could it be a bad processing this multiple simultaneous viewers in isard-stats-go?
• Thread is not disabled on fail
• Events are not sent to users right now, only managers and admins. Expected behaviour.
• Needs to check if there is data or not with one of this methods https://grafana.com/docs/grafana-cloud/data-configuration/agent/agent_monitoring/ or maybe just checking if there are started desktops in prometheus data.
• RDP GW keeps forever as a conected viewer once first connected. You close the remmina and it keeps connected.

Depends on !1966 (merged)