Image metadata (clli, mdcv, pasp, ...) should be assignable to `heif_image_handle`

[farindk]

Currently, we assign metadata properties (clli, mdcv, pasp) to the heif_image pixel image, but this does not work when images are composed (grid, iden, iovl). We need a way to assign these properties directly to the ImageItem (heif_image_handle).

• [x] grid
• [ ] tili
• [ ] iovl
• [ ] iden
• [ ] use colr from ImageExtraData::generate_property_boxes()
• [ ] add pixi to ImageExtraData