Add "debug to" alternative

[jakubklimek]

Now, "debug to" executes all components up to the selected one, including the selected one.
However, in cases where a failing component has many inputs, it might be beneficial to have a possibility to compute the whole pipeline up to the component, but not actually running the component, so that the component can be debugged safely based on already having all the inputs computed in a previous, correctly finished execution.