feat: use Stringer in getFunctionName when available (ExecuteActivity)#2050

LukaGiorgadze wants to merge 2 commits intotemporalio:mastertemporalio/sdk-go:masterfrom

LukaGiorgadze:support-stringer-in-activity-func-nameLukaGiorgadze/sdk-go:support-stringer-in-activity-func-nameCopy head branch name to clipboard