Use argparse for argument parsing

[mole99]

This PR simplifies argument parsing by using the builtin module argparse

• cace: Allows to specify a list of parameters cace cace/sky130_ef_ip__instramp.txt -s schematic --summary --parameter Idd_enabled psrr_100k

• cace-gui: captures console output only if --terminal is passed (not even for a short time)

This is in preparation for the multiprocessing rewrite.

[RTimothyEdwards]

Testing this: I immediately came up with the following error when running on sky130_ef_ip__instramp in cace-gui: "Error: No parameter named I found!" I tracked this down to cace_cli.py line 470 "for paramname in paramnames". There is no such expectation in the old code that "paramnames" would be a list; it is only a string (the parameter name) or None. In the original code, the argument was "paramname", not "paramnames".

If there is a new use case somewhere with a number of parameters being passed as a list, then you at least need above line 470:

        # In case only one parameter is passed in paramnames, convert to a list
        if isinstance(paramnames, str):
            paramnames = [paramnames]

Apart from that, it looks good. If you make that change, you can go ahead and merge it.

[mole99]

I fixed the bug by only ever passing a list to paramnames.

I have also updated the documentation with the new argument style.