Fix warnings (#2076)

* examples: Fix unused `Result` that must be used when initializing console_log

* examples: Fix unused imports

* Fix unread name field warning in linux x11 ime InputMethod struct

* Fix unread name field warning in linux x11 Device struct

* Ignore unread field warning in macos/ios MonitorHandle struct

* ci: Add `--deny warnings` to `RUSTFLAGS`

src/platform_impl/macos/monitor.rs

@@ -162,6 +162,7 @@ impl fmt::Debug for MonitorHandle {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         // TODO: Do this using the proper fmt API
         #[derive(Debug)]
+        #[allow(dead_code)]
         struct MonitorHandle {
             name: Option<String>,
             native_identifier: u32,