No type information in n-triples output

[kmRadiatorius]

When returning CONSTRUCT results as application/n-triples, qlever does not include type information for int, float and boolean types (and maybe some others as well). This breaks n-triples parsers, which expect type information to always be provided.

Example query:

PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>
PREFIX : <http://example.com#>

CONSTRUCT {
    :results :int ?int ;
             :float ?float ;
             :bool ?bool .
} WHERE {
     BIND ("1"^^xsd:nonNegativeInteger AS ?int)
     BIND ("1"^^xsd:float AS ?float)
     BIND ("true"^^xsd:boolean AS ?bool)
 }

Actual results:

<http://example.com#results> <http://example.com#int> 1 .
<http://example.com#results> <http://example.com#float> 1.0 .
<http://example.com#results> <http://example.com#bool> true .

Expected results:

<http://example.com#results> <http://example.com#int> "1"^^<http://www.w3.org/2001/XMLSchema#nonNegativeInteger> .
<http://example.com#results> <http://example.com#float> "1"^^<http://www.w3.org/2001/XMLSchema#float> .
<http://example.com#results> <http://example.com#bool> "true"^^<http://www.w3.org/2001/XMLSchema#boolean> .