Send the User Worker Identifier/Name along with the step parameter

[arvind-fluxon]

Is your feature request related to a problem? Please describe.
Yes, many times when we run "stage" based execution with a loopCount of 1, we end up not getting the data rolled over, since it depends on the iteration.

In order for us to have max parallelism, sometimes in the stage we try with a target of 100 users.
Now, each of these workers are unique as of Element, however, the actual code within behaves and gets the same data (from TestData) and even if we expose a different generator function, they cannot get unique values in each run.
As an alternate, its better to know the worker identifier within the step to pick and choose what's needed.