Enable SensitiveContentAnalysis for iOS 17+, MacOS 14+

Apple has a new framework for detecting "sensitive content", ie nudity, in images and videos. https://developer.apple.com/documentation/sensitivecontentanalysis

Reportedly all processing runs on the device, and no media is sent to Apple or to any other third party. So from a privacy perspective, that's pretty cool.

Saving our users from unwanted dick pics is also pretty cool.

On the next Apple OSes, we should check for this system setting, and if it's on, then we should use the framework to check image thumbnails and profile photos before displaying them.