feat: replace founding relation by membership relation

- Remove relations based on `ext:isFounderOfOrganization` predicate from the
  data model.
- Migrate the `ext:isFounderOfOrganization` triples to new, appropriate triples.

config/migrations/2023/20230824160000-related-organizations/20230824160500-founding-members.sparql

@@ -0,0 +1,35 @@
+PREFIX skos: <http://www.w3.org/2004/02/skos/core#>
+PREFIX org: <http://www.w3.org/ns/org#>
+PREFIX mu: <http://mu.semte.ch/vocabularies/core/>
+
+DELETE {
+  GRAPH ?g {
+    ?foundingOrg <http://mu.semte.ch/vocabularies/ext/isFounderOfOrganization> ?foundedOrg.
+  }
+}
+INSERT {
+  GRAPH ?g {
+    ?foundingOrg org:memberOf ?foundedOrg.
+
+    ?membership
+      a org:Membership;
+      mu:uuid ?uuid;
+      org:organization ?foundedOrg;
+      org:member ?foundingOrg;
+      org:role <http://data.lblod.info/id/rollen/73d5e1cf250d42fab15926771f07505a>.
+  }
+}
+WHERE {
+    VALUES ?g {
+      <http://mu.semte.ch/graphs/worship-service>
+      <http://mu.semte.ch/graphs/administrative-unit>
+      <http://mu.semte.ch/graphs/shared>
+    }
+
+    GRAPH ?g {
+      ?foundingOrg <http://mu.semte.ch/vocabularies/ext/isFounderOfOrganization> ?foundedOrg.
+    }
+
+  BIND(SHA1(CONCAT(STR(?foundingOrg), STR(?foundedOrg), "founded by")) as ?uuid)
+  BIND(IRI(CONCAT("http://data.lblod.info/id/lidmaatschap/", ?uuid)) AS ?membership)
+}