Fix custom namespace for cpp

[tom-hg57]

• Update generated cpp files created by cimgen
  • Fix custom namespace in cpp reader (e.g. entsoe in CGMES2, eu in CGMES3))
  • Fix custom namespace in cpp writer (e.g. "entsoe" in CGMES2, "eu" in CGMES3; using new generated functions getClassNamespaceUrl and getAttr>
  • Add function isAssignableFrom to fix parsing objects with changing types (e.g. first as Equipment, than as PowerTransformer)
• Add writeFile and writeCim to CIMWriter (write to just one file/stream, regardless of profiles)
• Fix custom namespace in cpp reader (e.g. entsoe in CGMES2, eu in CGMES3)
• Fix custom namespace in cpp writer (e.g. "entsoe" in CGMES2, "eu" in CGMES3; using new generated functions getClassNamespaceUrl and getAttributeNamespaceUrl)
• Fix isClassMatchingProfile in cpp writer (class is also matching if it contains attributes for the profile)
• Fix parsing objects with changing types (e.g. first as Equipment, than as PowerTransformer)
• Optimize reader performance (change Task::resolve() to const, don't erase tasks in resolveRDFRelations)
• Add unit tests
• Add installation of Boost to github workflows
• Add running of unit tests to build-src workflows
• Add installation of Boost to Dockerfile for packaging with cpack in release workflow
• Fix unit tests in github workflows
• Add missing documentation of parameter objList in CIMWriter.hpp