Windows shouldn't allow IME events when not editing text (On Desktop)

[liquidhelium]

Describe the bug
We can always enable or disable IME because IME is always allowed. In a typical application, this attribute should be determined by whether a text is being edited.

egui/crates/eframe/src/native/run.rs

Lines 563 to 572 in 0eabd89

	{
	integration.init_accesskit(gl_window.window(), self.repaint_proxy.lock().clone());
	}
	let theme = system_theme.unwrap_or(self.native_options.default_theme);
	integration.egui_ctx.set_visuals(theme.egui_visuals());
	gl_window.window().set_ime_allowed(true);
	if self.native_options.mouse_passthrough {
	gl_window.window().set_cursor_hittest(false).unwrap();
	}

egui/crates/eframe/src/native/run.rs

Lines 1011 to 1024 in 0eabd89

	wgpu_render_state.clone(),
	);
	#[cfg(feature = "accesskit")]
	{
	integration.init_accesskit(&window, self.repaint_proxy.lock().unwrap().clone());
	}
	let theme = system_theme.unwrap_or(self.native_options.default_theme);
	integration.egui_ctx.set_visuals(theme.egui_visuals());
	window.set_ime_allowed(true);
	{
	let event_loop_proxy = self.repaint_proxy.clone();
	integration.egui_ctx.set_request_repaint_callback(move || {

To Reproduce
Steps to reproduce the behavior:

1. You'll need to have a input method editor.
2. Start a native egui app (on web it works fine) and you'll find that you can call up the IME when not editing (even there's no textedit).

Expected behavior
When editing, IME is allowed; Disallowed otherwise.

Screenshots

(IME is on it's initial position.)

Desktop (please complete the following information):

• OS: Windows 22H2 (Windows 11)

Additional context
There's a field mutable_text_under_cursor in egui::output::PlatformOutput.

currently it's used by eframe web, but it should also applicable to egui_winit or other crates.

[Barugon]

if [gl_]window.set_ime_allowed was called with true when a text edit gained focus and called with false when that text edit lost focus then the on-screen keyboard would properly show and hide on Linux devices like PinePhone and Librem 5.