Separate NULL PIN attack and Brute-Force PIN attack

[LowSkillDeveloper]

Just a suggestion:
I would like to be able to perform Null attacks separately from Brute-Force. For example, adding the "--null" parameter. To perform only NULL PIN attack for all points.

And also so that you can combine --pixie and --null, just to exclude Brute-Force PIN attack. So that pixie is executed first and then null.