fix: Sharding Issues & Cleanup (#2952)

* fix: Sharding causing constant heartbeat / identify spam

* misc: Remove wait param in connect

* misc: Wait 2.5 seconds before sending identify again if session is resumable

* misc: Remove useless destroy call

* nit: Capitalization

* fix: Identify on HELLO not connectionOpen

* misc: Add different intervals for identify after invalid session
- 2500 if we couldn't resume in time
- 5000 if we didn't have a session ID (per the docs on identify, that a client can only connect every 5 seconds)
- Otherwise, just identify again

* misc: Only clear heartbeat if shard is fully dead

Reconnect clears it otherwise

* fix: Accessing .length on a Collection

src/structures/Guild.js

@@ -88,7 +88,7 @@ class Guild extends Base {
    * @readonly
    */
   get shard() {
-    return this.client.ws.shards[this.shardID];
+    return this.client.ws.shards.get(this.shardID);
   }
 
   /* eslint-disable complexity */