Merge prototype version 0.5.0 staging branch into main

[Lazersmoke]

This is to collect and resolve all the merge conflicts that are about to result from the various great changes everyone is working on :)

Changes incorporated so far are listed below:

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• Implemented :dipole mode for LSWT via @Hao-Phys closes #88

• Add intensities_binned

• Refactored interface for intensity calculations

• Add load_nxs_binning_parameters

• Refactor file structure

• Merge SWT dipole calcs with intensity_formula

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[kbarros]

Great work Sam! I put some comments above for you to consider, but David's review will be more important.

[Lazersmoke]

Assuming the CI goes ok, I'll rebase/squash & merge this later today, hopefully in a sensible way