[Feature Request] Allow double spread page to rotate in selected direction

[AVM-1996]

If this is vague allow me to explain, currently when selecting the option to rotate and spread double page it will always rotate in +90 degree, some device cover tend work in favor while others don't like me for example and allowing the rotation to opposite, as in -90 degree, would be a quality of life for some people

For the time being I am going to flip them manually but if we can have this it might be of useful quality of life in the future