It now automatically sets the size to the current project's size, has a button to lock aspect ratio, and resizing based on percentage. Some UI changes to CreateNewImage too.
The lock aspect ratio button has been changed from a checkbox to a texture button and the template code has been refactored to use a Template class instead of enums. Only dark icons have been added for now.
The default image width, height and fill color are being used only when the program first launches. After that, if the user creates an image with changed settings, these settings are being kept.
