增加对Uint(?)，Ulong(?),Ushort(?)的支持

ModeTypeGenerator.cs

@@ -24,11 +24,11 @@ namespace FlutterCodeGenerator
                     duplicatedTime = _tempTypes[type];
                 }
                 duplicatedTime++;
-                if (type == typeof(int) || type == typeof(long) || type == typeof(short))
+                if (type == typeof(int) || type == typeof(long) || type == typeof(short) || type == typeof(uint) || type == typeof(ulong) || type == typeof(ushort))
                 {
                     return new IntModeType(argName);
                 }
-                else if (type == typeof(int?) || type == typeof(long?) || type == typeof(short?))
+                else if (type == typeof(int?) || type == typeof(long?) || type == typeof(short?) || type == typeof(uint?) || type == typeof(ulong?) || type == typeof(ushort?))
                 {
                     return new IntNullableModeType(argName);
                 }