[API v3] Maintenance Mode (#7367)

* WIP(maintenance): maintenance

* WIP(maintenance): working locale features

* fix(maintenance): don't translate info page target

* WIP(maintenance): start adding info page

* fix(maintenance): linting

* feat: Add container to maintenance info page

* fix(maintenance): add config.json edits
Also DRY variables for main vs info pages

* fix(maintenance): linting

* refactor(maintenance): further slim down variables

* refactor: Remove unnecessary variables

* fix: Correct string interpolation in maintenace view

* feat: Dynamically add time to maintenance pages

* maintenance mode: do not connect to mongodb

* fix(maintenance): clean up timezones etc.

* fix(maintenance): remove unneeded sprite

config.json.example

@@ -10,6 +10,7 @@
     "TEST_DB_URI":"mongodb://localhost/habitrpg_test",
     "NODE_ENV":"development",
     "CRON_SAFE_MODE":"false",
+    "MAINTENANCE_MODE": "false",
     "SESSION_SECRET":"YOUR SECRET HERE",
     "ADMIN_EMAIL": "you@example.com",
     "SMTP_USER":"user@example.com",