api: upgrade audio client to VoiceWS v3

src/Discord.Net.WebSocket/API/Voice/HelloEvent.cs

@@ -0,0 +1,10 @@
+using Newtonsoft.Json;
+
+namespace Discord.API.Voice
+{
+    internal class HelloEvent
+    {
+        [JsonProperty("heartbeat_interval")]
+        public int HeartbeatInterval { get; set; }
+    }
+}

src/Discord.Net.WebSocket/API/Voice/ReadyEvent.cs

@@ -1,5 +1,6 @@
-#pragma warning disable CS1591
+#pragma warning disable CS1591
 using Newtonsoft.Json;
+using System;
 
 namespace Discord.API.Voice
 {
@@ -14,6 +15,7 @@ namespace Discord.API.Voice
         [JsonProperty("modes")]
         public string[] Modes { get; set; }
         [JsonProperty("heartbeat_interval")]
+        [Obsolete("This field is errorneous and should not be used", true)]
         public int HeartbeatInterval { get; set; }
     }
 }

src/Discord.Net.WebSocket/API/Voice/VoiceOpCode.cs

@@ -1,4 +1,4 @@
-#pragma warning disable CS1591
+#pragma warning disable CS1591
 namespace Discord.API.Voice
 {
     internal enum VoiceOpCode : byte
@@ -11,11 +11,19 @@ namespace Discord.API.Voice
         Ready = 2,
         /// <summary> C→S - Used to keep the connection alive and measure latency. </summary>
         Heartbeat = 3,
-        /// <summary> C←S - Used to reply to a client's heartbeat. </summary>
-        HeartbeatAck = 3,
         /// <summary> C←S - Used to provide an encryption key to the client. </summary>
         SessionDescription = 4,
         /// <summary> C↔S - Used to inform that a certain user is speaking. </summary>
-        Speaking = 5
+        Speaking = 5,
+        /// <summary> C←S - Used to reply to a client's heartbeat. </summary>
+        HeartbeatAck = 6,
+        /// <summary> C→S - Used to resume a connection. </summary>
+        Resume = 7,
+        /// <summary> C←S - Used to inform the client the heartbeat interval. </summary>
+        Hello = 8,
+        /// <summary> C←S - Used to acknowledge a resumed connection. </summary>
+        Resumed = 9,
+        /// <summary> C←S - Used to notify that a client has disconnected. </summary>
+        ClientDisconnect = 13,
     }
 }