Enable Timing-Allow-Origin response header

[#1]

Description - please enable the https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Timing-Allow-Origin header on responses from your servers (especially the tracking server for Analytics)

Why is this feature important to you - By adding `Timing-Allow-Origin: *` we will be able monitor responses status/timings from our customers browsers to your servers, which will help us to detect network connectivity issues at scale (e.g. in cases of geographic or ISP issues).

How would you like the feature to work - By adding `Timing-Allow-Origin: *` to all server responses (especially the tracking server for Analytics)

Current Behaviour - No `Timing-Allow-Origin` response header is sent therefore it is impossible to determine whether there are any network connectivity issues at scale.