revert(api): decouple api from curriculum

This reverts commit c077ffe4b9
via PR #40703

api-server/server/models/about.js

@@ -0,0 +1,26 @@
+import { createActiveUsers } from '../utils/about.js';
+
+module.exports = function(About) {
+  const activeUsers = createActiveUsers();
+  let activeUsersForRendering = 0;
+  About.getActiveUsers = async function getActiveUsers() {
+    // converting to promise automatically will subscribe to Observable
+    // initiating the sequence above
+    const usersActive = await activeUsers.toPromise();
+    activeUsersForRendering = usersActive;
+    return usersActive;
+  };
+
+  About.getActiveUsersForRendering = () => activeUsersForRendering;
+
+  About.remoteMethod('getActiveUsers', {
+    http: {
+      path: '/get-active-users',
+      verb: 'get'
+    },
+    returns: {
+      type: 'number',
+      arg: 'activeUsers'
+    }
+  });
+};