[Tracking] C#/UApi: resolve TODOs

[TheArcaneBrony]

Generated at commit 57827bc9:

• extra/admin-api/Spacebar.UApi/Controllers/GuildStickerController.cs:14: // TODO proper response type
• extra/admin-api/Spacebar.UApi/Controllers/Applications/ApplicationRpcController.cs:27: // TODO: type is wrong, normally only `disclosures` is returned
• extra/admin-api/Spacebar.UApi/Program.cs:126: // TODO config
• extra/admin-api/Spacebar.UApi/Models/GuildTemplate.cs:6: // TODO: real schemas

[TheArcaneBrony]

New todo:

• extra/admin-api/Spacebar.UApi/Controllers/Applications/ApplicationRpcController.cs:16: // TODO: implement disclosures