The current implementation has some important issues on Windows. We will reintroduce the feature once we figure them out!
I have kept some of the changes in #945, like the new `keyboard::Modifiers` powered by `bitflags`.
This allows us to introduce a platform-specific `Action` to both `iced_native`
and `iced_web` and remove the `Clipboard` from `Application::update` to maintain
purity.
Additionally, this should let us implement further actions to let users query
and modify the shell environment (e.g. window, clipboard, and more!)
A `Message` should represent an application event (e.g. user
interactions, command results, subscription results...). Therefore, it
should always consist of pure, cloneable data.
Using an `Application` with `executor::Null` does not make sense, as the
whole purpose of an `Application` is to allow executing async actions.
When async actions are not needed, `Sandbox` should be used instead.
