cmd/ctr, service/containers: implement container filter

Signed-off-by: Stephen J Day <stephen.day@docker.com>

containers/containers.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"time"
 
+	"github.com/containerd/containerd/filters"
 	"github.com/gogo/protobuf/types"
 )
 
@@ -29,7 +30,10 @@ type RuntimeInfo struct {
 
 type Store interface {
 	Get(ctx context.Context, id string) (Container, error)
-	List(ctx context.Context, filter string) ([]Container, error)
+
+	// List returns containers that match one or more of the provided filters.
+	List(ctx context.Context, filters ...filters.Filter) ([]Container, error)
+
 	Create(ctx context.Context, container Container) (Container, error)
 	Update(ctx context.Context, container Container) (Container, error)
 	Delete(ctx context.Context, id string) error