Add tracking for "Ultra HDR JPG"

[gregbenz]

HDR image support is growing on the web and it will be important to understand which browsers and how widespread support is for HDR images.

Chrome Canary (on desktop and Android 14) now offer support for a gain map standard for HDR images as "Ultra HDR JPG". This format includes a secondary image and metadata to allow a single file to display in an optimal way on both SDR (standard dynamic rang) and HDR (high dynamic range) displays. https://developer.android.com/guide/topics/media/hdr-image-format Adobe has published sample JPG gain map images at https://helpx.adobe.com/camera-raw/using/gain-map.html

This format is inherently backwards compatible with any browser which supports JPG, but only one which supports both HDR and the new gain map standard will be able to properly display the HDR content. I would propose tracking a list of browsers which properly interpret the gain map.