This is a follow up patch on top of https://gerrit.wikimedia.org/r/c/mediawiki/extensions/CheckUser/+/594615
See: https://gerrit.wikimedia.org/g/mediawiki/extensions/CheckUser/+/53ffb05ad1e4e7b7a5fa419e2229f686ce662c36/includes/specials/SpecialCheckUser.php#1956 for details on how it should work.
There is already a placeholder for this at TimelineRowFormatter::getLinks
Summary from the AHT planning meeting: This task is for checking the links are laid out correctly in each row - we may need to make a small fix, or we may need to do nothing. T251465: Investigate how to handle SpecialCheckUserGetLinksFromRow on SpecialInvestigate is for adding the new hook.