- More code cleanup and codestyle updates

- Fixed some possible nullref exceptions
- Methods signatures now have up to 3 parameters before breakaing down each parameter in a separate line
- Method invocations have the same rule, except the first parameter will be in the same line as the invocation to prevent some ugliness when passing lambas as arguments
- Applied many more codestyles
- Extensions folder fully reformatted

src/NadekoBot/Services/Impl/YtdlOperation.cs

@@ -9,9 +9,7 @@ public class YtdlOperation
     private readonly string _baseArgString;
 
     public YtdlOperation(string baseArgString)
-    {
-        _baseArgString = baseArgString;
-    }
+        => _baseArgString = baseArgString;
 
     private Process CreateProcess(string[] args)
     {