LibraryPanels: Expose library panels in dashboard apiserver (#92213)

pkg/registry/apis/dashboard/legacy/testdata/postgres--query_panels-get_uid.sql

@@ -0,0 +1,10 @@
+SELECT p.id, p.uid, p.folder_uid,
+  p.created, created_user.uid as created_by,
+  p.updated, updated_user.uid as updated_by,
+  p.name, p.type, p.description, p.model
+  FROM "grafana.library_element" as p
+  LEFT OUTER JOIN "grafana.user" AS created_user ON p.created_by = created_user.id
+  LEFT OUTER JOIN "grafana.user" AS updated_user ON p.updated_by = updated_user.id
+  WHERE p.org_id = 1
+    AND p.uid = 'xyz'
+  ORDER BY p.id DESC