Use a library for command line processing

[Thihup]

One way of improving the usage of Piranha would be by having a good CLI. Currently, we're doing all the argument processing by hand, which is repetitive and error-prone.

There is the Picocli library which seems to be easy to use, can be compiled to native image, and does not have transitive dependencies.

Its documentation seems to be pretty good: https://picocli.info

Now we have three applications that would benefit from it: Piranha CLI, Piranha Micro, and Piranha Server

[manorrock]

Go for it!