VerifyProof additional constraint

[rianhughes]

In VerifyProof, the reconstructed path should always be a subset of the path to the leaf, if it diverges at any point then it should fail. Currently the following passes

t.Run("Simple binary trie - fail missing key", func(t *testing.T) {
        tempTrie := buildSimpleTrie(t)
        zero := trie.NewKey(250, []byte{0})
        expectedProofNodes := []trie.ProofNode{
            {
                Edge: &trie.Edge{
                    Path:  &zero,
                    Child: utils.HexToFelt(t, "0x05774FA77B3D843AE9167ABD61CF80365A9B2B02218FC2F628494B5BDC9B33B8"),
                },
            },
            {
                Binary: &trie.Binary{
                    LeftHash:  utils.HexToFelt(t, "0x0000000000000000000000000000000000000000000000000000000000000002"),
                    RightHash: utils.HexToFelt(t, "0x0000000000000000000000000000000000000000000000000000000000000003"),
                },
            },
        }

        root, err := tempTrie.Root()
        require.NoError(t, err)
        key1 := utils.HexToFelt(t, "0x4")   // Non-existent key
        val1 := new(felt.Felt).SetUint64(2) // key=0 has val=2
        assert.False(t, trie.VerifyProof(root, key1, val1, expectedProofNodes, crypto.Pedersen))
    })