TrigSteering, TrigDecisionMaker, TrigHypoCommonTools: Make ILvl1ResultAccessTool::getLvl1Result() const.
ILvl1ResultAccessTool::getLvl1Result() is used from the const method TrigDecisionMakerMT::execute(), so it also needs to be const.
Change the interface a bit to achieve this: return the result vector by value, rather than by const reference, and if a Lvl1Result object is created, return it directly, rather than requiring a separate call.
Also modernize the declaration/use of ILvl1ResultAccessTool.
Update other packages for interface changes.