OZG-6301 Create stub for OrganisationsEinheitRemoteService

alfa-service/src/main/java/de/ozgcloud/alfa/collaboration/OrganisationsEinheitHeader.java

+package de.ozgcloud.alfa.collaboration;
+
+public class OrganisationsEinheitHeader {
+
+}

alfa-service/src/main/java/de/ozgcloud/alfa/collaboration/OrganisationsEinheitRemoteService.java

+package de.ozgcloud.alfa.collaboration;
+
+import java.util.stream.Stream;
+
+class OrganisationsEinheitRemoteService {
+
+	public Stream<OrganisationsEinheitHeader> search(String searchBy) {
+		// TODO Auto-generated method stub
+		throw new UnsupportedOperationException("Unimplemented method 'search'");
+	}
+
+}