[Feature] Voice reconnection and resuming (#2873)

* Voice receive fix (use system-selected port)

* Update SocketGuild.cs

* Reconnect voice after moved, resume voice connection, don't invoke Disconnected event when is going to reconnect

* no more collection primitives

* Disconnected event rallback & dispose audio client after finished

* Update src/Discord.Net.WebSocket/Audio/AudioClient.cs

* Update src/Discord.Net.WebSocket/Audio/AudioClient.cs

---------

src/Discord.Net.WebSocket/ConnectionManager.cs

@@ -172,8 +172,8 @@ namespace Discord
 
             await _onDisconnecting(ex).ConfigureAwait(false);
 
-            await _disconnectedEvent.InvokeAsync(ex, isReconnecting).ConfigureAwait(false);
             State = ConnectionState.Disconnected;
+            await _disconnectedEvent.InvokeAsync(ex, isReconnecting).ConfigureAwait(false);
             await _logger.InfoAsync("Disconnected").ConfigureAwait(false);
         }