[cors] Add 'Range' to simple headers

Hello WebAppSec members,

The application I work on is latency-sensitive and uses the Media Source
API in concert with XHR to download media bytes. In order to avoid the
latency cost of a preflight to each host in our CDN, we have developed a
workaround where we use a 'range=' query arg to subset an existing
resource. This workaround is suboptimal, and we would prefer to use a Range
header, but the latency impact of the extra request has a significant
impact on quality of experience.

What are your thoughts regarding the addition of 'Range' as a simple
request header to allow for this use-case?

Thanks for your consideration!
Steve