Added and applied styles for private readonly fields, private fields to Extensions and Common folders.

- Some renamings and code cleanups
- Chained method calls, binary expressions and binary patterns will now break into newlines
- Type param constraints and base constructor calls will be on the new line

src/NadekoBot/Modules/Games/Common/Trivia/TriviaGame.cs

@@ -196,8 +196,7 @@ public class TriviaGame
 
                 var umsg = imsg as SocketUserMessage;
 
-                var textChannel = umsg?.Channel as ITextChannel;
-                if (textChannel is null || textChannel.Guild != Guild)
+                if (umsg?.Channel is not ITextChannel textChannel || textChannel.Guild != Guild)
                     return;
 
                 var guildUser = (IGuildUser)umsg.Author;