feat(cms): add management for partnerships, history, accreditation, admissions, and policies pages

Implement a singleton page content system to manage static informational pages. This includes:
- New controllers, models, and data files for Partnerships, History, Accreditation, Admissions, and Policies.
- Admin routes and views for updating page content.
- Public API endpoints for fetching page data.
- Migration scripts for initializing page data.
- Updated admin navigation layout to include a dropdown for "About" sections.
- Audit action constants for tracking updates to these pages.

controllers/policiesController.js

@@ -0,0 +1,11 @@
+const PoliciesPage = require("../models/policiesPage");
+const AUDIT_ACTIONS = require("../constants/auditAction");
+const pageContentConfig = require("../utils/pageContentConfig");
+const createPageContentController = require("./_createPageContentController");
+
+module.exports = createPageContentController({
+  model: PoliciesPage,
+  modelName: "PoliciesPage",
+  auditAction: AUDIT_ACTIONS.UPDATE_POLICIES,
+  editorConfig: pageContentConfig.policies,
+});