Add self_video to VoiceState (#2137)

* Add self_video to VoiceState

* Update selfVideo flag

src/Discord.Net.Rest/API/Common/VoiceState.cs

@@ -28,6 +28,8 @@ namespace Discord.API
         public bool Suppress { get; set; }
         [JsonProperty("self_stream")]
         public bool SelfStream { get; set; }
+        [JsonProperty("self_video")]
+        public bool SelfVideo { get; set; }
         [JsonProperty("request_to_speak_timestamp")]
         public Optional<DateTimeOffset?> RequestToSpeakTimestamp { get; set; }
     }

src/Discord.Net.Rest/Entities/Users/RestGroupUser.cs

@@ -41,6 +41,8 @@ namespace Discord.Rest
         /// <inheritdoc />
         bool IVoiceState.IsStreaming => false;
         /// <inheritdoc />
+        bool IVoiceState.IsVideoing => false;
+        /// <inheritdoc />
         DateTimeOffset? IVoiceState.RequestToSpeakTimestamp => null;
         #endregion
     }

src/Discord.Net.Rest/Entities/Users/RestGuildUser.cs

@@ -223,6 +223,8 @@ namespace Discord.Rest
         /// <inheritdoc />
         bool IVoiceState.IsStreaming => false;
         /// <inheritdoc />
+        bool IVoiceState.IsVideoing => false;
+        /// <inheritdoc />
         DateTimeOffset? IVoiceState.RequestToSpeakTimestamp => null;
         #endregion
     }

src/Discord.Net.Rest/Entities/Users/RestWebhookUser.cs

@@ -131,6 +131,8 @@ namespace Discord.Rest
         /// <inheritdoc />
         bool IVoiceState.IsStreaming => false;
         /// <inheritdoc />
+        bool IVoiceState.IsVideoing => false;
+        /// <inheritdoc />
         DateTimeOffset? IVoiceState.RequestToSpeakTimestamp => null;
         #endregion
     }