qosify: add package for simple qos based on ebpf+cake

qosify: add package for simple qos based on ebpf+cake

qosify is simple daemon for setting up and managing CAKE along with a custom
eBPF based classifier that sets DSCP fields of packets.

It is configured via UCI and it supports the following features:
- simple TCP/UDP port based mapping
- IP address based mapping
- priority boosting based on average packet size
- bulk flow detection based on number of packets per second
- dynamically add IP entries with timeout

Signed-off-by: Felix Fietkau <nbd@nbd.name>