Support tracing XDP

[Asphaltt]

Fix #239

Support tracing XDP

Add an option --filter-trace-xdp to trace all XDP progs on host by fentry-ing on the progs, like the way tracing tc-bpf https://github.com/Asphaltt/pwru/commit/2347755900fffe100ab9eebaa180bb9f482df6fb.

The diff from tracing tc-bpf:

1. Not support to filter mark.
2. No mark in meta output.
3. No proto in meta output.
4. Not support --output-skb.

Example with --filter-trace-xdp --filter-trace-tc:

./pwru --filter-trace-xdp --filter-trace-tc --output-limit-lines 10 --filter-func 'xxx' --output-meta --output-tuple icmp
2024/03/04 14:26:47 Listening for events..
               SKB    CPU          PROCESS                     FUNC
0xffffbb8cc062cc28      7     [<empty>(0)]               dummy(xdp) netns=4026531840 mark=0x0 iface=2(ens33) proto=0x0000 mtu=1500 len=98 192.168.241.1:0->192.168.241.128:0(icmp)
0xffff95ed4596aa00      7     [<empty>(0)]                dummy(tc) netns=4026531840 mark=0x0 iface=2(ens33) proto=0x0800 mtu=1500 len=98 192.168.241.1:0->192.168.241.128:0(icmp)
0xffffbb8cc062cc28      7     [<empty>(0)]               dummy(xdp) netns=4026531840 mark=0x0 iface=2(ens33) proto=0x0000 mtu=1500 len=98 192.168.241.1:0->192.168.241.128:0(icmp)
0xffff95ed4596ba00      7     [<empty>(0)]                dummy(tc) netns=4026531840 mark=0x0 iface=2(ens33) proto=0x0800 mtu=1500 len=98 192.168.241.1:0->192.168.241.128:0(icmp)
0xffffbb8cc062cc28      7     [<empty>(0)]               dummy(xdp) netns=4026531840 mark=0x0 iface=2(ens33) proto=0x0000 mtu=1500 len=98 192.168.241.1:0->192.168.241.128:0(icmp)
0xffff95ed4596a700      7     [<empty>(0)]                dummy(tc) netns=4026531840 mark=0x0 iface=2(ens33) proto=0x0800 mtu=1500 len=98 192.168.241.1:0->192.168.241.128:0(icmp)
0xffffbb8cc062cc28      7     [<empty>(0)]               dummy(xdp) netns=4026531840 mark=0x0 iface=2(ens33) proto=0x0000 mtu=1500 len=98 192.168.241.1:0->192.168.241.128:0(icmp)
0xffff95ed4596b500      7     [<empty>(0)]                dummy(tc) netns=4026531840 mark=0x0 iface=2(ens33) proto=0x0800 mtu=1500 len=98 192.168.241.1:0->192.168.241.128:0(icmp)
0xffffbb8cc062cc28      7     [<empty>(0)]               dummy(xdp) netns=4026531840 mark=0x0 iface=2(ens33) proto=0x0000 mtu=1500 len=98 192.168.241.1:0->192.168.241.128:0(icmp)
0xffff95ed4596b400      7     [<empty>(0)]                dummy(tc) netns=4026531840 mark=0x0 iface=2(ens33) proto=0x0800 mtu=1500 len=98 192.168.241.1:0->192.168.241.128:0(icmp)
2024/03/04 14:26:52 Printed 10 events, exiting program..