Add overloaded constructor for class esScale

To make use of various functions provided by tmEventSetup.hh to generate LUTs on the fly (i.e. tmeventsetup::getLut()), type conversions in the offline emulator (CMSSW) are required to construct tmeventsetup::esScale objects.

Required changes are adding an overloaded constructor to class tmeventsetup::esScale to permit creation of new scale objects to be used to generate LUTs.

namespace tmeventsetup {
class esScale
{
public:
  ...
  esScale(const std::string& name, ...) : name_(name), ... {}
};
} // namespace tmeventsetup