Full beamline time-of-flight lookup table

[nvaytet]

Some monitors can be placed between choppers and even before the first choppers.
Until now, we only covered a range of distances in the tof lookup table that started after the last chopper in the cascade.

This PR generalizes the mechanism so we can build LUTs for the full beamline range.
For Odin, it now looks as follows:

Note that the SimulationResults class has changed, it is now a dict of event readings at various places along the beamline. Each reading is now essentially what the SimulationResults used to be before.
Note however that despite this change, no updates to the workflow that computes a LUT were necessary (e.g. notebooks for Odin and Dream).

The only small difference (apart from widening the LtotalRange) is that it is likely that we need to increase the LookupTableRelativeErrorThreshold parameter in these notebooks, as the mixing of wavelengths is high at small distances, before the first choppers.

[nvaytet]

Using 0 here raised the "No simulation reading found for distance -0.2m." error

[nvaytet]

Could optimize here instead of starting the search from the beginning every time, but not sure the added complexity (probably involving keeping track of an index for the relevant component reading) is worth the (probably minimal) performance gain?