[#194] pkg/container: Implement container constructor with format check

Implement NewVerifiedFromV2 function that verifies format of NeoFS API V2
Container message.

Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>

pkg/container/fmt_test.go

@@ -0,0 +1,49 @@
+package container_test
+
+import (
+	"testing"
+
+	"github.com/google/uuid"
+	"github.com/nspcc-dev/neofs-api-go/pkg"
+	"github.com/nspcc-dev/neofs-api-go/pkg/container"
+	containerV2 "github.com/nspcc-dev/neofs-api-go/v2/container"
+	"github.com/stretchr/testify/require"
+)
+
+func TestNewVerifiedFromV2(t *testing.T) {
+	cnrV2 := new(containerV2.Container)
+
+	errAssert := func() {
+		_, err := container.NewVerifiedFromV2(cnrV2)
+		require.Error(t, err)
+	}
+
+	// set unsupported version
+	v := pkg.SDKVersion()
+	v.SetMajor(0)
+	require.Error(t, pkg.IsSupportedVersion(v))
+	cnrV2.SetVersion(v.ToV2())
+
+	errAssert()
+
+	// set supported version
+	v.SetMajor(2)
+	require.NoError(t, pkg.IsSupportedVersion(v))
+	cnrV2.SetVersion(v.ToV2())
+
+	errAssert()
+
+	// set invalid nonce
+	nonce := []byte{1, 2, 3}
+	cnrV2.SetNonce(nonce)
+
+	errAssert()
+
+	// set valid nonce
+	uid := uuid.New()
+	data, _ := uid.MarshalBinary()
+	cnrV2.SetNonce(data)
+
+	_, err := container.NewVerifiedFromV2(cnrV2)
+	require.NoError(t, err)
+}