Installs nftables config useful for pmOS::

1) drop all connections to wwan* (wildcard matching supported, are there
   any other wwan iface names that wouldn't match this?)

2) allow ssh, drop from wwan (kinda redundant w/ the first rule, but
   doesn't hurt..), allow DHCP on usb*

3) allow all incoming connections on usb* (with the -openusb subpackage)

4) enable logging all nftable events (with the -log subpackage), very
   useful for debugging

fixes #1024