tests: Use make_realm to create type-correct realm objects.

Another step in the direction of improving node tests
and using type-correct organic data as much as possible.

web/tests/popover_menus_data.test.cjs

@@ -3,6 +3,7 @@
 const assert = require("node:assert/strict");
 
 const {make_user_group} = require("./lib/example_group.cjs");
+const {make_realm} = require("./lib/example_realm.cjs");
 const {mock_esm, zrequire} = require("./lib/namespace.cjs");
 const {run_test} = require("./lib/test.cjs");
 const $ = require("./lib/zjquery.cjs");
@@ -69,7 +70,7 @@ mock_esm("../src/group_permission_settings", {
 
 const current_user = {};
 set_current_user(current_user);
-const realm = {};
+const realm = make_realm();
 set_realm(realm);
 
 // Define test users