1312: Implement initial vocabulary browsing mechanism

Task-Url: https://pm.winseda.de/issues/1312

messages_de.properties

@@ -455,6 +455,7 @@
 ~eu.dariah.de.minfba.search.view.dataset.label.document_count                                   = Dokumente, die \u00FCber den konfigurierten Endpunkt verf\u00FCgbar sind.
 ~eu.dariah.de.minfba.search.view.filter.more                                                    = weitere...
 ~eu.dariah.de.minfba.search.view.filters.location                                               = Ort
+~eu.dariah.de.minfba.search.view.filters.provider                                               = Datenlieferant
 ~eu.dariah.de.minfba.search.view.filters.subject                                                = Genre
 ~eu.dariah.de.minfba.search.view.item.additional_data                                           = Weiterf\u00FChrende Daten
 ~eu.dariah.de.minfba.search.view.item.admin_data                                                = Informationen f\u00FCr Administratoren

messages_en.properties

@@ -335,6 +335,7 @@
 ~eu.dariah.de.minfba.search.view.dataset.label.document_count                                   = Documents that are available through the configured endpoint.
 ~eu.dariah.de.minfba.search.view.filter.more                                                    = more...
 ~eu.dariah.de.minfba.search.view.filters.location                                               = Location
+~eu.dariah.de.minfba.search.view.filters.provider                                               = Data provider
 ~eu.dariah.de.minfba.search.view.filters.subject                                                = Subject
 ~eu.dariah.de.minfba.search.view.item.additional_data                                           = Additional Data
 ~eu.dariah.de.minfba.search.view.item.admin_data                                                = Administrator information