Support RedisTimeSeries (#1757)

* Implement missing commands and add test

* Update DECRBY.spec.ts

* Small changes

* clean code

* Update MGET_WITHLABELS.ts

Use map in transformReply

Co-authored-by: leibale <leibale1998@gmail.com>

packages/time-series/lib/commands/MADD.ts

@@ -1,5 +1,7 @@
 import { Timestamp, transformTimestampArgument } from '.';
 
+export const FIRST_KEY_INDEX = 1;
+
 interface MAddSample {
     key: string;
     timestamp: Timestamp;