Move NAT settings from settings nat44 to a proper location.
Rename nat44 hierarchy to nat nat44 for consistency.
set vpp nat nat44 ... set vpp nat nat44 session-limit <u32> set vpp nat nat44 timeout icmp <u32> set vpp nat nat44 timeout tcp-established <u32> set vpp nat nat44 timeout tcp-transitory <u32> set vpp nat nat44 timeout udp <u32>