ctr: add some metric item
ctr: add some metric item

add memory limit, pid info into metric subcommand, since moby also
show them. As blkio read/write IO need more calculation，not add them.

Signed-off-by: Ace-Tang <a967bc6ab01ace27203ca6ab9fd77fbd3b598184@126.com>

crosbymichael/containerd,dmcgowan/containerd,dmcgowan/containerd,thaJeztah/containerd,miaoyq/containerd,vdemeester/containerd,estesp/containerd,mikebrow/containerd,thaJeztah/containerd,miaoyq/containerd,containerd/containerd,vdemeester/containerd,containerd/containerd,crosbymichael/containerd,estesp/containerd,mikebrow/containerd