Add recently added prog types to `bpftool prog` and attach types to
`bpftool cgroup`.

Update bpftool documentation and bash completion appropriately.
Signed-off-by: NAndrey Ignatov <rdna@fb.com>
Acked-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>