(reporting/settings) option to flush all local netflow data. closes https://github.com/opnsense/core/issues/983

(rrd) add configd "systemhealth flush" command, add flush single report. closes https://github.com/opnsense/core/issues/984

Bravely assisted by: @ShaRose

(interface groups) trigger missing to notify changed interface administration, closes https://github.com/opnsense/core/issues/1064

Language correction: more generic expression

PR: https://forum.opnsense.org/index.php?topic=1668

(fw, alias) refactor update_alias_names_upon_change to support nested alias renaming, closes https://github.com/opnsense/core/issues/1028

legacy_interface_stats using the wrong interface name. reference https://github.com/opnsense/core/issues/1014

This reverts commit 2fa901e8.

This reverts commit 4638d99c.