How to Test Multisite Locally

1. Implement feat: support multisite switch via domain name #873 changes in your branch.
2. In Django CMS Admin, add a "Site".
3. In Django CMS Admin, configure both "Sites" to use different domain names e.g.
   • localhost
   • 0.0.0.0
4. Visit local instance of site at different domains e.g.
   • localhost
   • 0.0.0.0
5. Verify any site-specific content/behavior is as expected.