Simplify tid1500 code to use the latest features of dcmsr

[fedorov]

From @jriesmeier:

DCMTK 3.6.3 is out now! https://blog.jriesmeier.com/2018/02/dcmtk-363/

And, after that I could finally push my changes regarding TID 4019 to the repository: http://git.dcmtk.org/?p=dcmtk.git;a=commit;h=d9c3b87

This will allow to simplify the process of populating report content for the components that were not supported at the time of writing it: https://github.com/QIICR/dcmqi/blob/master/apps/sr/tid1500writer.cxx#L296

Once done, this will also be a good time to update DCMTK version in 3D Slicer.