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`

examples/web.rs

@@ -51,7 +51,7 @@ mod wasm {
 
     #[wasm_bindgen(start)]
     pub fn run() {
-        console_log::init_with_level(log::Level::Debug);
+        console_log::init_with_level(log::Level::Debug).expect("error initializing logger");
 
         super::main();
     }