feat: support to mark direct traffic

[mzz2017]

### Mark for direct/must_direct outbound
# Mark is useful when you want to redirect traffic to specific interface (such as wireguard) or other advanced uses.
# Traffic from LAN will not be forwarded by dae to archive higher performance if lan_nat_direct is off (you can set it
# off only if you are sure dae is on a bridge device).

# An example of redirecting Disney traffic to wg0 is given here.
# You need set ip rule and ip table like this:
# 1. Set all traffic with mark 0x800/0x800 to use route table 1145:
# >> ip rule add fwmark 0x800/0x800 table 1145
# >> ip -6 rule add fwmark 0x800/0x800 table 1145
# 2. Set default route of route table 1145:
# >> ip route add default dev wg0 scope global table 1145
# >> ip -6 route add default dev wg0 scope global table 1145
# Notice that interface wg0, mark 0x800, table 1145 can be set by preferences, but cannot conflict.
# 3. Set routing rules in dae config file.
domain(geosite:disney) -> direct(mark: 0x800)