Mode parameters should be available also with explicit flag names

[afronski]

I would like to open discussion here about the usability of our CLI modes.

Currently, most of the modes uses implicit order of parameters, e.g.,

perun convert A.json B.yaml
perun convert A.yaml B.json --pretty-print

That's good. However, I would love to have it available also under explicit parameter names:

perun convert A.json B.yaml
perun convert --from=A.json --to=B.yaml

perun convert A.yaml B.json --pretty-print
perun convert --from=A.yaml --to=B.json --pretty-print

I know that will complicate the implementation, but maybe advantages are more significant than drawbacks.

[maxiwoj]

AFAIK it will significantly complicate the code and the usage of the tool - the kingpin cli arguments parser is not designed for this, but I'll create a quick PR for everyone to see.