[Tracking] C#/Admin API: resolve TODOs

[TheArcaneBrony]

Generated at commit 57827bc9:

• extra/admin-api/Spacebar.AdminApi/Controllers/TestControllers/IpcTestController.cs:43: // TODO: create type
• extra/admin-api/Spacebar.AdminApi/Controllers/TestControllers/EmptyDmsController.cs:27: // TODO channel type enum
• extra/admin-api/Spacebar.AdminApi/Controllers/GuildController.cs:149: // TODO: gateway events
• extra/admin-api/Spacebar.AdminApi/Controllers/ChannelController.cs:25: // TODO: proper type
• extra/admin-api/Spacebar.AdminApi/Controllers/UserController.cs:193: // yield break; // TODO