Remove trailing commas on wallet account ls output

The trailing commas is inconvenient:

1. For users trying to select an account id by double-clicking it in a terminal: the comma gets included in the selection
2. For dev parsing the `wallet account list` output: the commas needs to be handled

wallet/src/cli/account.rs

@@ -288,7 +288,7 @@ impl WalletSubcommand for AccountSubcommand {
                                 .iter()
                                 .map(|(id, chain_index)| format!("{chain_index} Private/{id}")),
                         )
-                        .format(",\n");
+                        .format("\n");
 
                     println!("{accounts}");
                     return Ok(SubcommandReturnValue::Empty);