Fix a few warnings

- configure_input_player_widget.cpp: always better to use `const auto &`
  whenever possible
- profiler.cpp: `ev->pos()` is deprecated, replace with
  `ev->position()`, which returns floats, thus the addition of
  `.toPoint()` (same as what's happening in `pos()`)
- game_list.cpp: `QString::SplitBehavior` is deprecate, use `Qt::`
  namespace instead