[PM-6153] Dedicated redis connection for rate limiter (#3763)

* rearrange how redis is registered

* separate redis connection string for rate limiter

src/Core/Settings/GlobalSettings.cs

@@ -520,6 +520,7 @@ public class GlobalSettings : IGlobalSettings
 
     public class DistributedIpRateLimitingSettings
     {
+        public string RedisConnectionString { get; set; }
         public bool Enabled { get; set; } = true;
 
         /// <summary>