Public key comparison methods panic with infinite operand

[cthulhu-rider]

Current Behavior

Following methods panic if at least one operand is infinite:

• https://pkg.go.dev/github.com/nspcc-dev/neo-go/pkg/crypto/keys#PublicKey.Equal
• https://pkg.go.dev/github.com/nspcc-dev/neo-go/pkg/crypto/keys#PublicKey.Cmp

Expected Behavior

no panic

Possible Solution

pre-check the case

Steps to Reproduce

func TestPubCmp(t *testing.T) {
	var pub1 keys.PublicKey
	require.NoError(t, pub1.DecodeBytes([]byte{0x00}))
	pk, err := keys.NewPrivateKey()
	require.NoError(t, err)
	pub2 := pk.PublicKey()
	t.Run("equal", func(t *testing.T) {
		require.NotPanics(t, func() { pub1.Equal(pub2) })
	})
	t.Run("cmp", func(t *testing.T) {
		require.NotPanics(t, func() { pub1.Cmp(pub2) })
	})
}

Context

testing the NeoFS cryprography using keys pkg

Regression

no

Your Environment

• Version of the product used: v0.107.2