Adding BitsStored entry and fixing DoseScaling entry
- Introduce the entry BitsStored into the saved dose file as it is required if PixelData is present and such was causing a failure in some cases.
- Changed DoseScaling to use sstream instead of the simply std::to_string as when the DoseScaling value was too small as was the case for TROTS calibration it was putting zero in the DICOM i.e.
$ std::to_string(1e-12)
"0.000000"