Minor fixes for manual tests

[notZaki]

While trying some of the tests in tests/manual_tests, I encountered a few FileNotFoundErrors because:

• the settings file points to s1.dcm but the example data folder contains S1.dcm
  • maybe this would've worked fine on an operating system with case-insensitive paths
  • resolved by changing the filename in the settings files
• rdsr_normalizer couldn't find the normalization_settings.json file because it wasn't copied over during the package installation
  • resolved by adding the settings json file into MANIFEST.in

[BwKodex]

Thanks for finding and fixing these bugs!