feat: add node iterator to MerkleTree

src/merkle/node.rs

@@ -0,0 +1,9 @@
+use super::Word;
+
+/// Representation of a node with two children used for iterating over containers.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct InnerNodeInfo {
+    pub value: Word,
+    pub left: Word,
+    pub right: Word,
+}