[misc] move /user/activate into a module (#2962)

* [misc] move /user/activate into a module

Co-Authored-By: Nate Stemen <nate.stemen@overleaf.com>

* [misc] setup copybara for the new user-activate module

* [misc] move the /user/activate route behind a feature flag

...which is by default enabled.

Co-authored-by: Nate Stemen <nate.stemen@overleaf.com>
GitOrigin-RevId: 87fc5ae869a7e282ffdbeea0ff7b7c55b8b9b31b

services/web/modules/user-activate/app/src/UserActivateRouter.js

@@ -0,0 +1,17 @@
+const logger = require('logger-sharelatex')
+const Settings = require('settings-sharelatex')
+const UserActivateController = require('./UserActivateController')
+const AuthenticationController = require('../../../../app/src/Features/Authentication/AuthenticationController')
+
+module.exports = {
+  apply(webRouter) {
+    if (Settings.disableModule['user-activate']) {
+      logger.log({}, 'Skipping Init UserActivate router')
+      return
+    }
+    logger.log({}, 'Init UserActivate router')
+
+    webRouter.get('/user/activate', UserActivateController.activateAccountPage)
+    AuthenticationController.addEndpointToLoginWhitelist('/user/activate')
+  }
+}