- 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/Db/Models/DelMsgOnCmdChannel.cs

@@ -6,13 +6,9 @@ public class DelMsgOnCmdChannel : DbEntity
     public bool State { get; set; }
 
     public override int GetHashCode()
-    {
-        return ChannelId.GetHashCode();
-    }
+        => ChannelId.GetHashCode();
 
     public override bool Equals(object obj)
-    {
-        return obj is DelMsgOnCmdChannel x
-               && x.ChannelId == ChannelId;
-    }
+        => obj is DelMsgOnCmdChannel x
+           && x.ChannelId == ChannelId;
 }