feat: make ioredis configurable via environment variables (#3365)

* feat: expose ioredis client options

* run linter

* refactor redis client init into class extension

* explicitly handle constructor errors

* rename singletons

server/utils/queue.ts

@@ -1,8 +1,7 @@
 import Queue from "bull";
-import Redis from "ioredis";
 import { snakeCase } from "lodash";
 import Metrics from "@server/logging/metrics";
-import { client, subscriber } from "../redis";
+import Redis from "../redis";
 
 export function createQueue(
   name: string,
@@ -13,10 +12,10 @@ export function createQueue(
     createClient(type) {
       switch (type) {
         case "client":
-          return client;
+          return Redis.defaultClient;
 
         case "subscriber":
-          return subscriber;
+          return Redis.defaultSubscriber;
 
         default:
           return new Redis(process.env.REDIS_URL);