Deerlab cost value different to scipy verbose output

[HKaras]

The cost function returned to the user in the FitResult function is different to the one shown in the verbose output of the fit function. This verbose output comes direct from scipy.least_squares. This should be clearly documented as it is a source of confusion.

[HKaras]

I do not understand the purpose of this line:

https://github.com/JeschkeLab/DeerLab/blob/4dcdcc221edc41f39f1ae91ae3dd341c0c55d772/deerlab/solvers.py#L761

This definition of fvals/cost is very different to scipy and is the main cause of the issue. Otherwise the descripency is a factor of 2.