Support custom image crops not associated with an image size

[roborourke]

The media modal image editor is geared towards editing crops associated with any registered image size.

The block editor in WP 5.5 introduced an inline image editor that allows for rotating and cropping. We would need to add support for a UI where no image size is specified but we extract crop / resize and rotation data from an existing Tachyon URL, then provide a UI to edit that.