Send ASCII chars from USB serial to selected widget (#1708)

* Initial commit for keyboard emulation
* Added on_keyboard to some widgets
* TextEdit partly
* Multi key send at once
* Frequency control support
* Fix encoder emulation
* Add keyboard to geomap
* More widgets

firmware/application/event_m0.cpp

@@ -242,6 +242,18 @@ void EventDispatcher::emulateTouch(ui::TouchEvent event) {
     on_touch_event(event);
 }
 
+void EventDispatcher::emulateKeyboard(ui::KeyboardEvent event) {
+    on_keyboard_event(event);
+}
+
+void EventDispatcher::on_keyboard_event(ui::KeyboardEvent event) {
+    // send the key to focused widget, or parent if not accepts it
+    auto target = context.focus_manager().focus_widget();
+    while ((target != nullptr) && !target->on_keyboard(event)) {
+        target = target->parent();
+    }
+}
+
 void EventDispatcher::on_touch_event(ui::TouchEvent event) {
     /* TODO: Capture widget receiving the Start event, send Move and
      * End events to the same widget.