Clean up Vocabulary

[woutslabbinck]

• Use the proper libary -> import { createVocabulary } from 'rdf-vocabulary';
• Use the ones defined in the ODRL-Evaluator when possible: https://github.com/SolidLabResearch/ODRL-Evaluator/blob/09aede5276ce6a0a1a991b40868925d57b49404f/src/util/Vocabularies.ts#L8