support new `prefer_s3_links` config property

[miles-grant-ibigroup]

Checklist

• [x] Appropriate branch selected (all PRs must first be merged to dev before they can be merged to master)
• [x] Any modified or new methods or classes have helpful JavaDoc and code is thoroughly commented
• [x] The description lists all applicable issues this PR seeks to resolve
• [x] The description lists any configuration setting(s) that differ from the default settings
• [x] All tests and CI builds passing
• [x] The description lists all relevant PRs included in this release (remove this if not merging to master)
• [x] e2e tests are all passing (remove this if not merging to master)

Description

The new property changes the generated HTML to use s3 urls instead of the auto fetch URLS. All optional, no defaults changed.