AQM: Use CAKE as default qdisc where appropriate instead of fq_codel

AQM: Use CAKE as default qdisc where appropriate instead of fq_codel

This script configures CAKE as default qdisc where appropriate:

* It is not suitable to use any queue management on bridges/GRE/VTI/tun
  interfaces.
* On Internet-facing interfaces, CAKE is configured in "internet" mode
  whereas on any zones except RED, it is configured in "metro" mode

Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>
Signed-off-by: Arne Fitzenreiter <arne_f@ipfire.org>