(plugins, interfaces) add ifgroup type, filter in interfaces_groups_edit.php. for https://github.com/opnsense/core/issues/1455

(gwlb.inc) more cleanups, $ifname == $gateway_item['friendlyiface'] looks kind of impossible here, $ifname is unique and not in $gateway_item yet...

It's a bit funny that the help text indicates we can use tag/tagged with
NAT rules as well, because this was never implemented although it really
works.

(firewall) empty means "in"... confusing ;) https://github.com/opnsense/core/blob/17.1.2/src/etc/inc/filter.inc#L2314-L2315

(firewall) add port/address parsing to FilterRule(), should be backwards compatible with current config settings

(filter) filter_generate_port, why all this trickery?? it's either a valid port range or it's not. not need to overreact.

It's better to replace this now, the new style code won't include this "magic".

translation fix and fix copyright year

fix firewall widget:

(filter) because referential integrity isn't guaranteed, we need to check for existence of the interface. edge-case of https://github.com/opnsense/core/pull/1419

IF -> Interface ("If" can be wrongly translated to a conditional ->
using interface will fix this)
Unlock the cell width: This will prevent Firefox to write over the cell
range.