ezjscAjaxContent : Image's exif fields MakerNote and UserComment must be base64 encoded

Although it's not always reproducible, in some environments the attempt to access ezoe::browse ezjscore call will result in no content, in result of a failure to parse as json, an array that includes non properly encoded UFT8 characters.

steps to reproduce.

• Load an image with non utf8 content in exif fields into a site
• in an xml block field, attempt to select the image through a insert/edit object or image function
• IF you're affected with the encoding problem, the popup window will be blank