Finish server-side translations in controllers

app/controllers/auth/Forms.controller.js

@@ -21,7 +21,7 @@ class Forms extends FormController {
 
         return res.page('auth:login', {
             ...this.Vue.data({
-                login_message: req.session?.auth?.message || 'Please sign-in to continue.',
+                login_message: req.session?.auth?.message || req.T('auth.sign_in_to_continue'),
                 registration_enabled: await Setting.get('auth.allow_registration')
             }),
         })
@@ -29,7 +29,7 @@ class Forms extends FormController {
 
     async logout_provider_present_success(req, res, next) {
         return this.Vue.auth_message(res, {
-            message: 'You have been successfully logged out.',
+            message: req.T('auth.logged_out'),
             next_destination: '/',
         })
     }