Fix lints, error on lint issues

.cargo/config

@@ -1,4 +1,7 @@
 [target.'cfg(all())']
 rustflags = [
-
+    "-Dclippy::all",
+    "-Dlet_underscore_drop",
+    "-Aclippy::assertions_on_result_states",
+    "-Aclippy::let_unit_value",
 ]

app/src/gui/deposit.rs

@@ -41,7 +41,7 @@ impl Deposit {
             .add_enabled(amount.is_ok() && fee.is_ok(), egui::Button::new("deposit"))
             .clicked()
         {
-            let _ = app.deposit(
+            let _result = app.deposit(
                 amount.expect("should not happen"),
                 fee.expect("should not happen"),
             );

app/src/gui/miner.rs

@@ -19,7 +19,7 @@ impl Miner {
         let best_hash = &format!("{best_hash}")[0..8];
         ui.monospace(format!("{best_hash}..."));
         if ui.button("mine").clicked() {
-            let _ = app.mine();
+            let _result = app.mine();
         }
     }
 }

lib/src/node.rs

@@ -220,10 +220,10 @@ impl Node {
             bundle
         };
         if let Some(bundle) = bundle {
-            let _ = self
+            let () = self
                 .drivechain
                 .broadcast_withdrawal_bundle(bundle.transaction)
-                .await;
+                .await?;
         }
         Ok(())
     }