Migrate from urfave/cli v1 (maintenance mode) to v3 to benefit from
active development, improved features, and long-term support.
Signed-off-by: lifubang <lifubang@acmcoder.com>
The following commands are moved from `contrib/cmd` to `tests/cmd`:
- fs-idmap
- pidfd-kill
- recvtty
- remap-rootfs
- sd-helper
- seccompagent
Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>