Wrong behavior if Picture Tiling on custom types

Inside the nuxeo-platform-imaging-tiling-preview we have a problem because of TiledImagePreviewer that leads to a missing previews in some cases.

There are actually 2 potential problems that when present both will make the rendering of tiling to fail.

Problem 1 : TiledImagePreviewer not using Facets

the TiledImagePreviewer has not been updated to use the Picture facet.
As a results, it checks only on "Picture" type and then fall back on a compat mode.

Problem 2 : TiledImagePreviewer still uses imagingService.getImageMetadata

In the fallback, the tiling can not get the picture size from the Picture schema (because it thinks it is not there).
=> it calls imagingService.getImageMetadata

This API call will fallback on a java lib that may fail finding the correct size if the meta-data are not up to date.
=> it should use ImageMagick for that