Improve the root privielge check when kyanos start

[hengyoush]

Is your feature request related to a problem? Please describe.
When kyanos start we check whether it has root privielge, but this was not accurate, we should check whether we have the CAP_BPF via capget syscall

Describe the solution you'd like

import (
	"golang.org/x/sys/unix"
)

hdr := unix.CapUserHeader{Version: unix.LINUX_CAPABILITY_VERSION_3}	
var data [2]unix.CapUserData
err := unix.Capget(&hdr, &data[0])
haveBpfCap := data[0].Permitted&unix.CAP_BPF != 0

Describe alternatives you've considered
If you have a better solution, feel free to change it.