Timepix data frame(wavelength/tof) offset

[YooSunYoung]

The wavelength offset will be one of parameters to be fitted by the data analysis model.

It should be used for the workflow again to shift the wavelength coordinate by the offset it fitted.

It'll be simply adding one more provider/parameter but still not clear where exactly should it be done
i.e. right after loading or right after normalization

Once it's decided, it won't be a lot of work
but I'm writing an issue first since I'm not going to work on this right now : D....