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>

io/router/router.go

@@ -102,6 +102,11 @@ func (q *Router) TextInputState() TextInputState {
 	return q.kqueue.InputState()
 }
 
+// TextInputHint returns the input mode from the most recent key.InputOp.
+func (q *Router) TextInputHint() (key.InputHint, bool) {
+	return q.kqueue.InputHint()
+}
+
 // WriteClipboard returns the most recent text to be copied
 // to the clipboard, if any.
 func (q *Router) WriteClipboard() (string, bool) {