Replace getHighestGroupAction with ActionGateway method#1666

yookoala wants to merge 2 commits intoGibbonEdu:v26.0.00GibbonEdu/core:v26.0.00from

yookoala:refactor/deprecate-get-highest-group-actionyookoala/GibbonEduCore:refactor/deprecate-get-highest-group-actionCopy head branch name to clipboard