Implement iterative memory estimator for LPRec

[ferenc-gh]

No description provided.

[dkazanc]

thanks, please also check if FBP CuPy works, I did get an error on that branch:

data = _apply_horiz_detector_padding(data, self.Atools.detectors_x_pad, cupyrun)
                                               ^^^^^^^^^^^
AttributeError: 'RecToolsDIRCuPy' object has no attribute 'Atools'

[ferenc-gh]

Fixed missing Atools issue in: DiamondLightSource/httomolibgpu#248