feat(guild-realtime): add websocket gateway with api-key auth and channel rooms

Fabric.Backend.Guild/src/realtime/realtime.module.ts

@@ -0,0 +1,9 @@
+import { Global, Module } from '@nestjs/common';
+import { RealtimeGateway } from './realtime.gateway';
+
+@Global()
+@Module({
+  providers: [RealtimeGateway],
+  exports: [RealtimeGateway],
+})
+export class RealtimeModule {}