Move shift cascade vertex

[mhuen]

This PR removes the option to shift the cascade vertex to the shower maximum when reading in labels. Instead, the cascade model itself is now responsible for shifting the cascade vertex internally. This is the preferred way to handle this, since an externally applied shift in the labels will cause confusion down the line for the end user. This PR fixes issue #7

The PR also cleans up the models and configs and removes older configs. Some other changes include renaming of estimate_charge_distribution to charge_distribution_type and now requiring float_precision to be set. This previously was set to the default float32 to maintain backwards compatibility to older models that did not define the precision.

Version compatibilities are updated to reflect these breaking changes.