Generate list of Prebid Server automatic functionality

[bretg]

The Rules Taskforce has asked each PMC owning a codebase to generate a list of functionality that takes place automatically, and whether that functionality can be turned off by publishers.

Prebid's philosophy is that most functionality should be opt-in, and that any functionality that is automatic should be reviewed by Prebid Legal counsel and have the option for publishers to opt-out.

To seed the list, here are some things Prebid Server does by default without being specifically asked:

• anonymize request elements for all GDPR purposes - each account can override this behavior
• anonymize request elements for USP 'no-sale' - each account can override this behavior
• anonymize request elements COPPA and LMT - accounts cannot override this behavior
• Copy TCF-EU consent out of GPP string into original TCF location - accounts cannot override this behavior
• DSA validations - accounts cannot override this behavior
• Reads Privacy Sandbox HTTP headers for Topics and Testing Labels - accounts cannot override this behavior
• Cooperative User Syncing - host companies can set the default which accounts can override
• PBS-Java: geo-lookup is automatic when needed to help determine GDPR scope - accounts can turn off GDPR entirely.
• Add x-prebid HTTP header containing PBS version - accounts cannot override this behavior

Note: if a feature is triggered by a request parameter, it's not considered automatic. e.g. device.ext.prebid.interstitial.minheightperc