fix(electrum)!: Remove seen_at param from into_tx_graph

and `into_confirmation_time_tx_graph`, since now it makes
sense to use `TxGraph::update_last_seen_unconfirmed`.

Also, use `update_last_seen_unconfirmed` in examples for
electrum/esplora. We show how to update the last seen
time for transactions by calling `update_last_seen_unconfirmed`
on the graph update returned from a blockchain source, passing
in the current time, before applying it to another `TxGraph`.

example-crates/wallet_esplora_blocking/src/main.rs

@@ -53,8 +53,11 @@ fn main() -> Result<(), anyhow::Error> {
         })
         .collect();
 
-    let (update_graph, last_active_indices) =
+    let (mut update_graph, last_active_indices) =
         client.full_scan(keychain_spks, STOP_GAP, PARALLEL_REQUESTS)?;
+
+    let now = std::time::UNIX_EPOCH.elapsed().unwrap().as_secs();
+    let _ = update_graph.update_last_seen_unconfirmed(now);
     let missing_heights = update_graph.missing_heights(wallet.local_chain());
     let chain_update = client.update_local_chain(prev_tip, missing_heights)?;
     let update = Update {