enable jinja2 loopcontrols extension

PR: https://forum.opnsense.org/index.php?topic=2273.0

Not explained why added in 2012 and never touched since.  Also only
works on one device.

(network insight) work in progress, when local netflow collection is enabled it should be easy to test the progress so far by going to https://<address>/ui/diagnostics/networkinsight/

Brings it a littler close to how "services" category works now.

1,2,3, this is a test...