Add -v option to log inspected jars, detected properties files

[kasemir]

... and packages.
Since tool from #2390 may run for 30 seconds, this option provides feedback on the progress of parsing the files.

[tynanford]

I like this update. While the PR is open, can you add a check for len(jar_file_list) == 0 and print a message that no jar files are found? I thought that could be a hint that a build is needed first

[kasemir]

Since it's Friday..
I noticed that you're using type hints (product_location: str, ...) -> None.
Do they actually do anything, or is python support for type hints still mostly for documentation?
Are you using an editor where you get warnings when you pass parameters of the wrong type?

[tynanford]

Thanks for adding that.

Yeah they still don't do anything. I started to use them about a year ago mostly for documentation and a little hint to others... and because I personally think it would be nice if they were more standard. They can be nice if you use Pycharm too.

But it looks like the python devs specifically have said they won't ever mandate type hints: https://peps.python.org/pep-0484/#non-goals