Support configuration of Request headers CDN forwards to origin

[akf]

Amazon Cloudfront distributions can be configured to forward specific headers to the origin server and cache content based on those headers.

Of specific interest to our project is the Accept-Encoding header, which would enable us to serve compressed files to browsers. Amazon's documentation calls out several other scenarios that are probably worthy of support.

Notes

• See https://docs.aws.amazon.com/AmazonCloudFront/latest/DeveloperGuide/header-caching.html
• Slack discussion

Acceptance Criteria

• Determine next steps and acceptance criteria