Update validate and versions, refactor metadata and urls

[johnmhoran]

Reference: #247

[johnmhoran]

@JonoYang Please review when you have the chance. Looking forward to your suggestions and questions. This comprises my work (subject to input from you and colleagues) on the first four commands: metadata, urls, validate and versions.

I've substantially updated, refactored and supplemented purlcli.py, test_purlcli.py and the related test files. All make test tests passed, all GH checks passed, no apparent merge conflict with main per GH.

[JonoYang]

@johnmhoran I have some suggestions for you.

[johnmhoran]

@JonoYang I've addressed all of your comments and committed and pushed; all GH checks passed (I had to rerun a 3.10 push check that failed initially -- transitory validation warning for one of the PURLs in one of the tests).

[johnmhoran]

@JonoYang I'm taking a closer look at this, which doesn't look quite right. Maybe a copy-paste error on my part? Unable to find the possible source for that approach. This appears twice in purlcli.py.

log_file = Path(log_file=os.path.join(os.path.expanduser("~"), "app.log"))

Maybe it should be

log_file = Path(os.path.join(os.path.expanduser("~"), "app.log"))

Testing manually....

[johnmhoran]

@JonoYang Unable so far to manually trigger a pkg:deb/debian/* error, which is the only way I know to test the try/except. ;-) Will keep trying because I'm sure that example had excess text (which I've removed and am testing). The error will surely occur again ....

[johnmhoran]

@JonoYang I've replicated two rounds of the error followed by no error and see the app.log file gets created (in my Ubuntu-20.04 home/jmh/ directory) and populated properly and deleted in the next round as intended. I'll take care of running the main tests, commit and push this correction, and watch the GH checks run.

[johnmhoran]

@JonoYang All GH checks passed.

[JonoYang]

@johnmhoran Looking good, I have a comment about setting the log file location as a constant at the top of the file, under the import statements.

[JonoYang]

I see os.path.join(os.path.expanduser("~"), "app.log") referenced a few times through the code. I think it would be better to have this as a constant at the top of the file, like LOG_FILE_LOCATION = os.path.join(os.path.expanduser("~"), "app.log") and then use LOG_FILE_LOCATION in the necessary places.

I also think the log file should be named purlcli.log, or something that would indicate the log was created by purlcli

[johnmhoran]

Thank you @JonoYang -- I'll implement these improvements shortly. 👍

[johnmhoran]

@JonoYang Changes implemented, just one local failure with make test -- the usual minecode/tests/test_maven.py::MavenEnd2EndTest::test_visit_and_map_with_index -- and all GH checks passed.

[JonoYang]

Thanks! Merging this now