Make `python.call` operation idempotent-capable

[foreignmeloman]

Is your feature request related to a problem? Please describe

Currently python.call operation is not considered idempotent no matter what.

Describe the solution you'd like

Instead of the current behavior python.call operation can be modified to be shown as idempotent operation based on the return value of the function called with the following logic:

Return value	Operation status
None	Success (current behavior)
True	Success
False	No changes

This will enable to implement the idempotent logic in the function itself and correctly represent it in run report, while keeping the current behavior intact, when the function does not return anything.

[Fizzadar]

This is an excellent idea 👍

[simonhammes]

I agree. Wouldn't an enum be a better choice though (wrapped in Optional[] to keep BC)?