Ghost Roles: fix whitelist checks

[whatston3]

About the PR

Restores ghost role whitelist checks. Removed a few remaining "FRONTIER MERGE" comments with no relevance (commented code, unused imports).

Why / Balance

Error in previous upstream merge.

How to test

0. Build the game, should build fine.
1. Spawn with unwhitelisted account.
2. /ghost. Check roles, emotional/station pets should be disabled.
3. Comment out GhostRoleSystem.cs:598 (removes prototype, which the UI relies on to disable buttons).
4. Build, spawn with unwhitelisted account.
5. /ghost. Check roles, emotional/station pets should be enabled.
6. Click all available whitelisted roles. Nothing should happen (server-side checks on Takeover, JoinRaffle).

Media

Requirements

• I have read and I am following the Pull Request Guidelines. I understand that not doing so may get my pr closed at maintainer’s discretion
• I have added screenshots/videos to this PR showcasing its changes ingame, or this PR does not require an ingame showcase

Breaking changes

Changelog

🆑

• fix: Fixed ghost role whitelist requirement checks.

[dvir001]

Looks logical, didnt test in game yet.