INSPIRE / Update INSPIRE theme thesaurus

[fxprunayre]

now available in the INSPIrE registry (with new ids) http://inspire.ec.europa.eu/theme

[fxprunayre]

Instead of rebuilding this thesaurus from the list, add the possibility to import it from INSPIRE Registry based on https://github.com/geonetwork/core-geonetwork/issues/2500

[fxprunayre]

Previous version of the thesaurus:

<skos:Concept rdf:about="http://rdfdata.eionet.europa.eu/inspirethemes/themes/1">
<skos:altLabel>rs</skos:altLabel>
<skos:prefLabel xml:lang="sv">Referenskoordinatsystem</skos:prefLabel>

New version created from the registry:

<skos:Concept rdf:about="http://inspire.ec.europa.eu/theme/rs">
<skos:prefLabel xml:lang="en">Coordinate reference systems</skos:prefLabel>
<skos:scopeNote xml:lang="en">Systems for uniquely referencing spatial information in space as a set of coordinates (x, y, z) and/or latitude and longitude and height, based on a geodetic horizontal and vertical datum.</skos:scopeNote>
<skos:prefLabel xml:lang="fr">Référentiels de coordonnées</skos:prefLabel>
<skos:scopeNote xml:lang="fr">Systèmes de référencement unique des informations géographiques dans l'espace sous forme d'une série de coordonnées (x, y, z) et/ou la latitude et la longitude et l'altitude, en se fondant sur un point géodésique horizontal et vertical.</skos:scopeNote>

Changes at concept level:

• Ids are different
• altLabel is not available (use for INSPIRE icons) - maybe replaced by last "/" part of the id ?

Changes for INSPIRE thesaurus:

• file will be generated from INSPIRE Registry (see #2500)
• thesaurus filename will be different based on Registry. Proposal to use registry URL as a prefix to avoid collision so it will be httpinspireeceuropaeutheme-theme.rdf
• this thesaurus was also part of the installer, should we remove and let users load it from the admin ?