Fires Ready event after Resumed dispatch message is done

The Ready event isn't fired when the client recovers from being disconnected from Discord, this solves the gap between Connected and Ready for this case.

src/Discord.Net.WebSocket/DiscordSocketClient.cs

@@ -519,6 +519,7 @@ namespace Discord.WebSocket
                                             await GuildAvailableAsync(guild).ConfigureAwait(false);
                                     }
 
+                                    await _readyEvent.InvokeAsync().ConfigureAwait(false);
                                     await _gatewayLogger.InfoAsync("Resumed previous session").ConfigureAwait(false);
                                 }
                                 break;