Remove work directories for processes where input has a specific value

[valterschutz]

My nextflow processes often invoke python scripts, which might change as I develop them. Thus, I often end up wanting to rerun a process but only for a very limited set of inputs.

Unlike #5308 and #6683 , I don't want to change the caching behavior. I just want to remove specific work directories, so that nextflow understands that some processes need to rerun.

I first propose that nextflow clean is extended with an option to invalidate a specific process, e.g. nextflow clean -process <process>. I currently achieve the same behavior by temporarily disabling the cache for that specific process, but I think this would be a more convenient solution.

My second proposal is that the above command is additionally extended to support the syntax nextflow clean -process <process> -input-name <input_name> -input-value <input_value>. For the time being, I mostly care about this working with integers and strings.

For my personal workflow --- which is largely based on training reinforcement learning agents --- this is (IMO) the biggest issue of Nextflow, which I am otherwise very impressed by. I'm surprised that I haven't found anyone else suggesting this yet. Am I missing something obvious?