app, io: [wasm, android] add support for numeric/email keyboard mode

Previously, the on-screen keyboard always displays the text keyboard,
(QWERTY or equivalent).

For optimal user experience, it's possible to specify the keyboard type
using `InputHint`. The on-screen keyboard will provide shortcuts or
restrict what the user can input.

Due to some limitations (gio#116), only numeric and text keyboards are
supported on Android.

Signed-off-by: Inkeliz <inkeliz@inkeliz.com>

app/internal/wm/os_windows.go

@@ -665,6 +665,8 @@ func loadCursor(name pointer.CursorName) (syscall.Handle, error) {
 
 func (w *window) ShowTextInput(show bool) {}
 
+func (w *window) SetInputHint(_ key.InputHint) {}
+
 func (w *window) HDC() syscall.Handle {
 	return w.hdc
 }