Rework `Match`

[louisroyer]

• InnerIpSrc should not be inside Header: we have Payload for this…

type Match struct {
    Gtp GtpLayer
    Ip IpLayer
}
type IpLayer struct {
    Src netip.Addr
    Dst netip.Addr
}

type GtpLayer struct {
    Ip IpLayer // outer Ip
    Udp UdpLayer 
    Teid
}

func (l GtpLayer) Fteid() Fteid {
    return Fteid{Addr: l.Ip.Dst, Teid: Teid}
}