feat: page tree browser

client/graph/common/common-pages-query-tree.gql

@@ -0,0 +1,11 @@
+query ($parent: Int!, $mode: PageTreeMode!, $locale: String!) {
+  pages {
+    tree(parent: $parent, mode: $mode, locale: $locale) {
+      id
+      path
+      title
+      isFolder
+      parent
+    }
+  }
+}