note and hash cleanup

noir-projects/aztec-nr/aztec/src/note/note_and_hash.nr

@@ -1,6 +1,9 @@
-use crate::note::note_interface::NoteInterface;
-
+/// When obtaining notes via `get_notes(...)` a note hash is computed for each note when constraining it (and a read
+/// request is created and passed to kernels). This same note hash (called note_hash_for_read_request) is needed when
+/// removing notes. Since computing this hash is expensive and since it is needed when removing a note we return it
+/// from the `get_notes(...)` function. The purpose of this struct is to couple the note and the note hash and make it
+/// easier to pass these values around.
 struct NoteAndHash<Note> {
    note: Note,
-   hash: Field,
+   hash: Field, // (note_hash_for_read_request)
 }