Provide Mapping of MIME Types for CAE Image Variant Links

When building links to image variants in the CAE, the MIME type of the original image is used by default to determine the file extension of the links. To adjust these MIME types you can now provide a mapping of original MIME types to desired MIME types in the setting linkMimeTypeMapping . For details see section "Images" below "Website Management" in the Blueprint Developer Manual.

(CMS-22884)