Add engine commands built on containerd

This new collection of commands supports initializing a local
engine using containerd, updating that engine, and activating
the EE product

Signed-off-by: Daniel Hiltgen <daniel.hiltgen@docker.com>

cli/command/engine/activate_test.go

@@ -0,0 +1,37 @@
+package engine
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/docker/cli/internal/containerizedengine"
+	"gotest.tools/assert"
+)
+
+func TestActivateNoContainerd(t *testing.T) {
+	testCli.SetContainerizedEngineClient(
+		func(string) (containerizedengine.Client, error) {
+			return nil, fmt.Errorf("some error")
+		},
+	)
+	cmd := newActivateCommand(testCli)
+	cmd.Flags().Set("license", "invalidpath")
+	cmd.SilenceUsage = true
+	cmd.SilenceErrors = true
+	err := cmd.Execute()
+	assert.ErrorContains(t, err, "unable to access local containerd")
+}
+
+func TestActivateBadLicense(t *testing.T) {
+	testCli.SetContainerizedEngineClient(
+		func(string) (containerizedengine.Client, error) {
+			return &fakeContainerizedEngineClient{}, nil
+		},
+	)
+	cmd := newActivateCommand(testCli)
+	cmd.SilenceUsage = true
+	cmd.SilenceErrors = true
+	cmd.Flags().Set("license", "invalidpath")
+	err := cmd.Execute()
+	assert.Error(t, err, "open invalidpath: no such file or directory")
+}