feat: mobile map mode (#9717)

Signed-off-by: fufesou <linlong1266@gmail.com>

flutter/lib/models/input_model.dart

@@ -544,8 +544,7 @@ class InputModel {
       handleKeyDownEventModifiers(e);
     }
 
-    // * Currently mobile does not enable map mode
-    if ((isDesktop || isWebDesktop) && keyboardMode == kKeyMapMode) {
+    if (isMobile || (isDesktop || isWebDesktop) && keyboardMode == kKeyMapMode) {
       // FIXME: e.character is wrong for dead keys, eg: ^ in de
       newKeyboardMode(
           e.character ?? '',