Fix expansion implementation to produce the expected order in the failing JSON-LD test suite tests

[marcelotto]

Affected tests:

• Expansion
  • Test 0034 - Multiple properties expanding to the same IRI
  • Test 0035 - Language maps with @vocab, default language, and colliding property
  • Test 0038 - Expanding blank node labels
• Flattening
  • Test 0034 - Multiple properties expanding to the same IRI
  • Test 0035 - Language maps with @vocab, default language, and colliding property
  • Test 0038 - Flattening blank node labels
• Transform JSON-LD to RDF
  • Test 0118 - produce generalized RDF flag