max_number_of_predictions parameter not considered during story testing

[akelad]

When running rasa test, during story evaluation it seems like the max_number_of_predictions parameter in the processor isn't taken into account. This means if there's stories with a lot of actions in a row (>10 by the default parameter), the tests will pass, but when a user talks to the bot the circuit breaker will be tripped.

During action prediction when talking to the bot, the _predict_and_execute_next_action function in the processor gets executed, whereas during the test it's the predict_next_action function.

We should make it so that the predict_next_action function also takes the max_number_of_predictions parameter into account