Perturbing charge can lead to negative charge

[pweigel]

When a perturbation_dict is provided to the graph definition with a setting for charge, it can lead to negative charges since it is sampled from a normal distribution (if you are unlucky, like me):
https://github.com/graphnet-team/graphnet/blob/92b150aa5fbe149cdd7d473932d05375df176417/src/graphnet/models/graphs/graph_definition.py#L348C1-L362C30

Possible solution: include bounds for the perturbations. If the sampled value is outside of the bounds, then it is resampled.