FMassProcessingPhaseManager::OnPhaseStart

Called by the given Phase at the very start of its execution function (the [FMassProcessingPhase::ExecuteTick](API\Plugins\MassEntity\FMassProcessingPhase\ExecuteTick)), even before the [FMassProcessingPhase.OnPhaseStart](API\Plugins\MassEntity\FMassProcessingPhase\OnPhaseStart) broadcast delegate