[EAK-526] Add custom ImageUpload widget

[liubou-masiuk]

The OOTB coral fileupload/imageupload widget has several issues and can potentially be fixed

• validation
• storing data in a subnode
• pathpicker functionality
• ability to configure video instead of an image

potentially we can recreate the imageupload widget in the toolkit and fix these issues

Questions:

• will this widget use the same imageupload annotation or a new one?
• will we base our widget on the granite one, or recreate from scratch?