Improvements and fixes

A plant's "Networking" page now offers "Abort scan" for a running network scan and "Regenerate peer config" for a WireGuard site's connection file. Availability figures for a plant's VPN connections no longer show gaps.

• A running network scan can now be stopped on a plant's "Networking" page with "Abort scan", keeping the devices already found.
• A device deleted on a plant's "Networking" page stays deleted after the on-site agent next reports what it found.
• Availability figures for a plant's VPN connections no longer show gaps after the on-site agent restarted or a connection switched between WireGuard and OpenVPN.
• A WireGuard site's connection file can now be rebuilt with "Regenerate peer config", keeping its name, subnets and address while the on-site agent restarts once.