[#973] ir: Listen and process Put/Delete events of Subnet contract

Define notification events, implement parsers. Add morph client of
Subnet contract. Listen, verify and approve events in Inner Ring app.

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

pkg/innerring/processors/subnet/put_test.go

@@ -0,0 +1,115 @@
+package subnetevents
+
+import (
+	"errors"
+	"testing"
+
+	ownertest "github.com/nspcc-dev/neofs-sdk-go/owner/test"
+	"github.com/stretchr/testify/require"
+
+	"github.com/nspcc-dev/neofs-sdk-go/owner"
+	"github.com/nspcc-dev/neofs-sdk-go/subnet"
+	subnetid "github.com/nspcc-dev/neofs-sdk-go/subnet/id"
+)
+
+type put struct {
+	idEvent
+
+	creator owner.ID
+
+	creatorErr error
+
+	info subnet.Info
+
+	infoErr error
+}
+
+func (x put) ReadCreator(id *owner.ID) error {
+	if x.creatorErr != nil {
+		return x.creatorErr
+	}
+
+	*id = x.creator
+
+	return nil
+}
+
+func (x put) ReadInfo(info *subnet.Info) error {
+	if x.infoErr != nil {
+		return x.infoErr
+	}
+
+	*info = x.info
+
+	return nil
+}
+
+func TestPutValidator_Assert(t *testing.T) {
+	var (
+		v PutValidator
+
+		e put
+
+		err error
+	)
+
+	// read ID error
+	e.idErr = errors.New("id err")
+
+	err = v.Assert(e)
+	require.ErrorIs(t, err, e.idErr)
+
+	e.idErr = nil
+
+	// zero subnet ID
+	subnetid.MakeZero(&e.id)
+
+	err = v.Assert(e)
+	require.ErrorAs(t, err, new(zeroSubnetOp))
+
+	const idNum = 13
+	e.id.SetNumber(idNum)
+
+	// read creator error
+	e.creatorErr = errors.New("creator err")
+
+	err = v.Assert(e)
+	require.ErrorIs(t, err, e.creatorErr)
+
+	e.creatorErr = nil
+
+	// read info error
+	e.infoErr = errors.New("info err")
+
+	err = v.Assert(e)
+	require.ErrorIs(t, err, e.infoErr)
+
+	e.infoErr = nil
+
+	// diff explicit ID and the one in info
+	var id2 subnetid.ID
+
+	id2.SetNumber(idNum + 1)
+
+	e.info.SetID(id2)
+
+	err = v.Assert(e)
+	require.ErrorIs(t, err, errDiffID)
+
+	e.info.SetID(e.id)
+
+	// diff explicit creator and the one in info
+	var creator2 owner.ID
+
+	creator2 = *ownertest.GenerateID()
+
+	e.info.SetOwner(creator2)
+
+	err = v.Assert(e)
+	require.ErrorIs(t, err, errDiffOwner)
+
+	e.info.SetOwner(e.creator)
+
+	err = v.Assert(e)
+	require.NoError(t, err)
+}