Restrict maximum size of ObjectHead Oracle NeoFS response

[AnnaShaleva]

The problem is described at nspcc-dev/neofs-api#171 (comment) and similar to neo-project/neo-modules#803. Currently the size of received object header isn't restricted in any way, getHeader and getHash Oracle NeoFS protocol methods are affected. See the usages of getObjHeader:

neo-go/pkg/services/oracle/neofs/neofs.go

Lines 162 to 176 in 871ee18

	func getObjHeader(ctx context.Context, c *client.Client, addr *oid.Address) (*object.Object, error) {
	var headPrm client.PrmObjectHead
	headPrm.FromContainer(addr.Container())
	headPrm.ByID(addr.Object())
	res, err := c.ObjectHead(ctx, headPrm)
	if err != nil {
	return nil, err
	}
	var obj = object.New()
	if !res.ReadHeader(obj) {
	return nil, errors.New("missing header in the reply")
	}
	return obj, nil
	}

[roman-khimov]

To be fixed by nspcc-dev/neofs-api#262, nothing to do on NeoGo side.