chore: implement cli list organization members (#13555)

example cli command: 
`coder organization members`

cli/organizationmembers_test.go

@@ -0,0 +1,36 @@
+package cli_test
+
+import (
+	"bytes"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"github.com/coder/coder/v2/cli/clitest"
+	"github.com/coder/coder/v2/coderd/coderdtest"
+	"github.com/coder/coder/v2/coderd/rbac"
+	"github.com/coder/coder/v2/testutil"
+)
+
+func TestListOrganizationMembers(t *testing.T) {
+	t.Parallel()
+
+	t.Run("OK", func(t *testing.T) {
+		t.Parallel()
+
+		ownerClient := coderdtest.New(t, &coderdtest.Options{})
+		owner := coderdtest.CreateFirstUser(t, ownerClient)
+		client, user := coderdtest.CreateAnotherUser(t, ownerClient, owner.OrganizationID, rbac.RoleUserAdmin())
+
+		ctx := testutil.Context(t, testutil.WaitMedium)
+		inv, root := clitest.New(t, "organization", "members", "-c", "user_id,username,roles")
+		clitest.SetupConfig(t, client, root)
+
+		buf := new(bytes.Buffer)
+		inv.Stdout = buf
+		err := inv.WithContext(ctx).Run()
+		require.NoError(t, err)
+		require.Contains(t, buf.String(), user.Username)
+		require.Contains(t, buf.String(), owner.UserID.String())
+	})
+}