Specify the image path and size for additional images in CMS

Currently when adding additional images in the CMS, it allows you to input a height and width, however it also reuses the medium image path to generate the correct path. If the medium image path has a size argument, it results in the image outputting two size arguments and resetting to the default size of 200x200.

We could improve this by allowing the users to input a imagepath for the additional images so it doesn't reuse the medium image path.