refactor: refactor crypto APIs to use RpoDigest instead of Word

src/merkle/node.rs

@@ -1,9 +1,9 @@
-use super::Word;
+use crate::hash::rpo::RpoDigest;
 
 /// 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,
+    pub value: RpoDigest,
+    pub left: RpoDigest,
+    pub right: RpoDigest,
 }