Add a resolver

This commit adds a resolver to the toplevel Distillery domain, to allow
resolving domains globally.

distillery/resources/compose/barrel/wisskiutils/list_uri_prefixes.php

@@ -0,0 +1,19 @@
+<?php
+
+/**
+ * This script will list all the URIs that this system is aware of.
+ * This works by listing all the default graph uris of all the adapters.
+ */
+
+// iterate over all adapters
+$storage = \Drupal::entityTypeManager()->getStorage('wisski_salz_adapter');
+foreach ($storage->loadMultiple() as $adapter) {
+    // read the configuration, and check if we have a default graph
+    $conf = $adapter->getEngine()->getConfiguration();
+    if(!array_key_exists('default_graph', $conf)) {
+        continue;
+    }
+
+    // and echo it out
+    echo $conf['default_graph'] . "\n";
+}