Fix various typos

Mainly fix typos in comments, but also some minor code changes:

* Rename `apply_on_poiner` to `apply_on_pointer`.
* Rename `ImeState::Commited` to `ImeState::Committed`
* Correct `cfg_attr` usage: `wayland_platfrom` -> `wayland_platform`.

src/platform_impl/ios/app_state.rs

@@ -551,7 +551,7 @@ pub fn did_finish_launching(mtm: MainThreadMarker) {
         //
         // relevant iOS log:
         // ```
-        // [ApplicationLifecycle] Windows were created before application initialzation
+        // [ApplicationLifecycle] Windows were created before application initialization
         // completed. This may result in incorrect visual appearance.
         // ```
         let screen = window.screen();