Add `--filter enabled=true` for `docker plugin ls`
Add `--filter enabled=true` for `docker plugin ls`

This fix adds `--filter enabled=true` to `docker plugin ls`,
as was specified in 28624.

The related API and docs has been updated.

An integration test has been added.

This fix fixes 28624.

Signed-off-by: Yong Tang <765086fe2e0c1f980161f127fec596800f327f62@outlook.com>

Zebrilee/cli,dnephin/cli,thaJeztah/cli,e11137/cli,docker/cli,thaJeztah/cli,docker/cli,ashfall/cli,Zebrilee/cli,allencloud/cli,ashfall/cli,riyazdf/cli,allencloud/cli,gdevillele/cli,e11137/cli,redpanda/cli,riyazdf/cli,cpuguy83/cli,redpanda/cli,dnephin/cli,cpuguy83/cli