add default chapter order setting

[Valle_reading_manga]

As the title suggests, I think it'd be nice to add a user setting to allow specifying a preferred sorting order for chapters. This'd both be a QoL improvement and remove an unnecessary request (for titles requiring pagination), loading chapters in the preferred order directly when navigating to a title rather than having to change the sorting order first.
There is a somewhat related suggestion although not exactly the same, so let me know if I should go upvote that one instead...