docs: trace-log MUTXO info in wallet-updater

Implement `Display` for `MonitoredUtxo` and trace-log this output in the
wallet-state method that updates the wallet state with a new block.

This feature was inspired by the bug hunt leading to #328.

src/models/state/wallet/monitored_utxo.rs

@@ -1,5 +1,7 @@
 use std::collections::VecDeque;
+use std::fmt::Display;
 
+use itertools::Itertools;
 use serde::Deserialize;
 use serde::Serialize;
 use tasm_lib::triton_vm::prelude::Tip5;
@@ -40,6 +42,45 @@ pub struct MonitoredUtxo {
     pub abandoned_at: Option<(Digest, Timestamp, BlockHeight)>,
 }
 
+impl Display for MonitoredUtxo {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        let aocl_leaf_index = match self.get_latest_membership_proof_entry() {
+            Some(msmp) => msmp.1.aocl_leaf_index.to_string(),
+            None => "not mined".to_owned(),
+        };
+        let spent = match self.spent_in_block {
+            Some((block_hash, block_timestamp, block_height)) => {
+                format!("spent in {block_hash}, at {block_timestamp}, block height {block_height}.")
+            }
+            None => "not spent".to_owned(),
+        };
+        let confirmed = match self.confirmed_in_block {
+            Some((block_hash, block_timestamp, block_height)) => {
+                format!(
+                    "received in {block_hash}, at {block_timestamp}, block height {block_height}."
+                )
+            }
+            None => "not mined yet".to_owned(),
+        };
+        let msmp_for_blocks = format!(
+            "valid MSMPs for blocks\n{}\n",
+            self.blockhash_to_membership_proof
+                .iter()
+                .map(|(digest, _)| digest)
+                .join("\n")
+        );
+
+        write!(
+            f,
+            "AOCL-leaf index: {aocl_leaf_index}\n\
+            {spent}\n\
+            {confirmed}\n\
+            {msmp_for_blocks}\n
+            "
+        )
+    }
+}
+
 impl MonitoredUtxo {
     pub(crate) fn new(utxo: Utxo, max_number_of_mps_stored: usize) -> Self {
         Self {

src/models/state/wallet/wallet_state.rs

@@ -980,6 +980,11 @@ impl WalletState {
         let (mut valid_membership_proofs_and_own_utxo_count, all_existing_mutxos) =
             preprocess_own_mutxos(monitored_utxos, new_block).await;
 
+        debug!(
+            "handling {} monitored UTXOs",
+            valid_membership_proofs_and_own_utxo_count.len()
+        );
+
         // Loop over all input UTXOs, applying all addition records. In each iteration,
         // a) Update all existing MS membership proofs
         // b) Register incoming transactions and derive their membership proofs
@@ -1147,6 +1152,10 @@ impl WalletState {
             valid_membership_proofs_and_own_utxo_count.values()
         {
             let mut monitored_utxo = monitored_utxos.get(*own_utxo_index).await;
+            trace!(
+                "Updating MSMP for MUTXO with wallet-index {own_utxo_index}; with AOCL leaf-index {}. MUTXO:\n{monitored_utxo}",
+                updated_ms_mp.aocl_leaf_index
+            );
             monitored_utxo.add_membership_proof_for_tip(new_block.hash(), updated_ms_mp.to_owned());
 
             // Sanity check that membership proofs of non-spent transactions are still valid