Input Validation [ Birth proccess, Death Proccess , Mutation Proccess]

[cbennington852]

There are several validation input issues regarding negative numbers.

1. The birth proccess input array allows the input of negative numbers. This causes an error,
   Example:
   birth_process=bdms.poisson.DiscreteProcess([2.0, -2.0, 2.0]),
   Error created:

  File "/home/ella/Documents/GitHub/BDMS/tests/runnable.py", line 36, in <module>
    tree.evolve(
  File "/home/ella/Documents/GitHub/BDMS/bdms/tree.py", line 340, in evolve
    raise TreeError(f"{capacity=} exceeded at time={current_time}")
bdms.tree.TreeError: 'capacity=2000 exceeded at time=-38.628032539305764' 

2. The mutation_proccess allows for negative numbers, this causes the package to run indefinitely, resulting in a timeout error.
   Example:
   mutation_process=bdms.poisson.ConstantProcess(-0.1),#BUG cannot be negative
   Similarly the death_proccess can also be negative.

[wsdewitt]

More generally, any concretized child class implementation of bdms.Process.λ should return non-negative float. We want:

• For bdms.poisson.ConstantProcess ensure self.value >= 0
• For bdms.poisson.DiscreteProcess ensure all(self.rates.values) if isinstance(self.rates, Mapping[Hashable, float]) else all(self.rates)

[cbennington852]

Awesome, I have created the purposed changes in the "charles-branch"

[wsdewitt]

Nice! When you're ready, please create a pull request for me to review.