Require login to connect to staging (#1360)

## Description:

Complete:
- Add support for cookie-based auth (ref
https://github.com/openfrontio/infra/pull/83)
- Restrict game server API access to users with a specific flare
- Restrict join game to users with a valid token and an allowed flare
- Unauthorized landing page
- Token cache
- Destroy token cookie on logout

## Please complete the following:

- [x] I have added screenshots for all UI updates
- [x] I process any text displayed to the user through translateText()
and I've added it to the en.json file
- [x] I have added relevant tests to the test directory
- [x] I confirm I have thoroughly tested these changes and take full
responsibility for any bugs introduced
- [x] I understand that submitting code with bugs that could have been
caught through manual testing blocks releases and new features for all
contributors

src/core/configuration/DevConfig.ts

@@ -42,6 +42,11 @@ export class DevServerConfig extends DefaultServerConfig {
   subdomain(): string {
     return "";
   }
+  allowedFlares(): string[] | undefined {
+    return [
+      // Require login but do not rqeuire any flares
+    ];
+  }
 }
 
 export class DevConfig extends DefaultConfig {