Add writer for 2D array string case

[njacazio]

No description provided.

[alibuild]

Error while checking build/O2/fullCI for a2be212 at 2023-11-21 20:43:

## sw/BUILD/O2-latest/log
c++: error: unrecognized command-line option '--rtlib=compiler-rt'
c++: error: unrecognized command-line option '--rtlib=compiler-rt'
c++: error: unrecognized command-line option '--rtlib=compiler-rt'
c++: error: unrecognized command-line option '--rtlib=compiler-rt'
/sw/SOURCES/O2/12290-slc8_x86-64/0/Framework/Core/include/Framework/VariantJSONHelpers.h:354:21: error: no matching function for call to 'rapidjson::Writer<rapidjson::BasicOStreamWrapper<std::basic_ostream<char> > >::String(std::__cxx11::basic_string<char>)'
ninja: build stopped: subcommand failed.

Full log here.