The `text` field on `KeyEvent` was hardcoded to `None` on Android,
making it impossible for custom `NativeActivity` subclasses that
show the IME to receive functional text input using *for example* the
existing `winit-egui` crate which relies on this field being set.
Use `Key::to_text()` on press events to derive `text` from
`logical_key`, matching the convention used by the Windows and macOS
backends.
Supposedly that doesn't include all kinds of special virtual unicode
keys, but at least the basics work this way.
Allow updating IME state atomically to make it easier for platforms
where it's atomic by its nature, like Wayland. The old API is marked
as deprecated and is routed to the new atomic API.
Co-authored-by: dcz <gilapfco.dcz@porcupinefactory.org>
