Add extension to query primary chromaticities / luminance data of a VkDisplayKHR from EDID

When working with HDR displays, it is often crucial for the application to have access to the native gamut and brightness range limitations of the corresponding display. There is currently a way to *signal* this metadata to the display (VK_EXT_hdr_metadata), but no way to do the inverse - querying the device limits of the display itself.

As a stop-gap compromise, you could add an extension to simply report the raw EDID and rely on the application using third party EDID parsing libraries.