[keyword-matcher] match the country and continent category

[pvgenuchten]

many unmatched terms relate to countries, projects, organisations and soiltypes
let's add them to the keyword matching
(we may later decide whether or not to add them to the filters on the catalogue or not)

• for country http://publications.europa.eu/resource/authority/country
• for soiltype https://agrovoc.fao.org/browse/agrovoc/en/page/c_7204
• for organisation (the best list is currently in the soilwise knowledge graph metadata>contact>organization)
• for projects (the best list is currently in the soilwise knowledge graph deliverable>fundedBy>project (grantnr))

[wbcbugfree]

Also for continent, we may use http://publications.europa.eu/resource/authority/continent