* feat: add gin_helper::Dictionary::ValueOrDefault()
A convenience function for using a default value if the
specified key isn't present in the dictionary.
* refactor: use ValueOrDefault() in native_window.cc
* refactor: use ValueOrDefault() in native_window_mac.mm
* refactor: use ValueOrDefault() in native_window_views.cc
* refactor: use ValueOrDefault() in electron_api_native_image.cc