Allow to rerun workflows

[pconesa]

if you have a "branch" that failed but want to re run it changing one parameter (box size), allow to rerun from that point:

I can foresee one problem now, what to do when there are "subsets" in the way?

This is similar to a "resume" in case something failed, alien to scipion, and want to resume but have protocols after it even with data......in streaming.