[Python-ideas] Add InvalidStateError to the standard exception hierarchy

I frequently find that I want to raise an exception when the target of a call is not in an appropriate state to perform the requested operation. Rather than choosing between `Exception` or defining a custom exception, it would be nice if there were a built-in `InvalidStateError` exception that my code could raise. In cases where I want to define a custom exception anyway, I think it would be nice if it could have a generic `InvalidStateError` exception class for it to inherit from. Of course, I would be open to other ideas for what the name of this exception should be. Other possibilities off the top of my head are `BadStateError` or `StateError`.