Query based on index file rather than limited list of resources

[mvanbrab]

Index file is an RDF file in a pod, example:

<http://example.com/index_xyz>
  <http://www.w3.org/2000/01/rdf-schema#seeAlso>
    <https://css5.onto-deside.ilabt.imec.be/texon/ceon/manuf1_1>,
    <https://css5.onto-deside.ilabt.imec.be/texon/ceon/manuf1_2>,
    <https://css5.onto-deside.ilabt.imec.be/texon/ceon/manuf1_3> .

where:

• <http://example.com/index_xyz> is a (configurable) subject in the index file
• <http://www.w3.org/2000/01/rdf-schema#seeAlso> is a (configurable) predicate
• <https://css5.onto-deside.ilabt.imec.be/texon/ceon/manuf1_1> (and others) are the resources to be queried by the final query

[mvanbrab]

Guide:

• Make a SPARQL query using https://query.linkeddatafragments.org/ (or https://webclient.onto-deside.ilabt.imec.be) to obtain resources from an example index file (for the moment, use this one: https://css5.onto-deside.ilabt.imec.be/texon/ceon/index_manufacturer.
• Prepare an extended format of config.json in the project to describe this new type of query-with-index-file.
• Then implement...