Add fit features for images

We've got an option to crop, resize and upsize an image. However, not always it's possible to predict in what orientation the user will upload an image so that rules resize: 300x300 and crop: 300x300 will result in either square image or rectangle because an image is landscape-oriented. Therefore there is a need in fit like in Intervention/Image so that it will be needed size always. Please, consider to add this option to image fields.