Consider returning a TypeError for ``.has_state()`` for state size 0

[JoelPasvolsky]

Currently returns a ValueError with a technically correct but not hugely helpful error message:

>>> from dwave.optimization import Model
>>> model = Model()
>>> i = model.integer(3, lower_bound=0, upper_bound=20)
>>> i.has_state()
ValueError: index out of range: 0

Would it make sense to capture the model.states.size() == 0 condition and if zero, return a TypeError with an explicit error message?

[arcondello]

Right, in this case you're implicitly doing i.has_state(index=0) and because you haven't initialized any states 0 is out of bounds. The error message could definitely be clearer. Will fix.

[arcondello]

Should be as simple as

        if not -num_states <= index < num_states:
            raise ValueError(
                f"state index {index} out of bounds. "
                "Initialize the state with model.states.resize(...)."
            )

if you want to fold it into #487