Import for files of type owl, rdf and ttl not working

[Mikoteko]

We cannot import files of the owl, rdf or ttl type.

The packages in the rdf_traitment.js are obsolete, we need to replace the packages rdf-parser-rdfxml, jsonld-streaming-parser etc.

Commented lines in file_convertor.js

Commented lines in rdf_traitment.js (import of RdfXmlParser & init of the parser + functions _rdf_traitmentXML and parseRDF)