Port PR from PBS-Go: Accounts: Add coop cookiesync priority groups

[cross-repo-issue-creation]

A PR was merged over on PBS-Go

• Accounts: Add coop cookiesync priority groups prebid-server#4561
• timestamp: 2025-10-09T18:58:29Z

[AntoxaAntoxic]

This feature has been already implemented in PBS Java. Functionally-wise both the PBS Go and PBS Java work in the same way, but there're some discrepancies in the account config: the priority_groups term is not used in the PBS Java, instead it's called prioritized_bidders which they actually are (even in the the PBS Go the list of priority groups is used as a list of prioritized bidders) The path and the data type are different as well: account.cookie_sync.pri as an array expected in Java vs account.cookie_sync.priority_groups as an array of arrays expected in Go.

I believe the issue can be closed.