Include context from transition when an action is dispatched from opc.evaluate.

[phil-kahrl]

When an action signature is in an APM as an "enter" or "exit" action, it would be great to have some context from the transition included when that action is dispatched from opc.evaluate(). Currently, inside an action bodyFunction there is no way to tell what the target state of the APM is for the invocation. Actions currently have access to the "__apmiStep" from the ocdi, but that will contain the step that was last written to the ocdi and not the step that the APM will be (potentially) transitioning to.

Similarly it would be nice to know within a bodyFunction of an action whether the action was invoked by an external actor as opposed to opc.evaluate(), because most actions will be intended for one manner of invocation or the other, but not both and there is currently no way to distinguish them at runtime.