[ESSDIFFRACTION] BEER improvements

[jokasimr]

Main changes are:

• Adds the modulation chopper modes to the list of chopper settings.
• Uses chopper parameters instead of mcstas specific parameters in modulation workflow, making it more ready for real data.
• Simplifies the McStas data loader using McstasTox - it needed some refactoring.

[jokasimr]

The changes look large and scary because of the lockfile, the non-lockfile changes are something like +850 -950.

[jokasimr]

Here is the dspacing spectrum obtained from the files in @celinedurniak linked to in #669.