Fix DCMTK dictionary crashes in plugins

Build it as a shared library in superbuild

CMakeExternals/DCMTK.cmake

@@ -60,7 +60,7 @@ if(NOT DEFINED DCMTK_DIR AND NOT ${CMAKE_PROJECT_NAME}_USE_SYSTEM_${proj})
     CMAKE_CACHE_ARGS
       ${ep_common_cache_args}
       ${ep_project_include_arg}
-      -DBUILD_SHARED_LIBS:BOOL=OFF
+      -DBUILD_SHARED_LIBS:BOOL=ON
       -DDCMTK_WITH_DOXYGEN:BOOL=OFF
       -DDCMTK_WITH_ZLIB:BOOL=OFF # see github issue #25
       -DDCMTK_WITH_OPENSSL:BOOL=OFF # see github issue #25