Add logging to have console launcher inform about bad/missing searchpath roots

[maxandersen]

as discussed in #4764 (reply in thread) it would useful if when running console cli to get info/debug log about directories and/or jars that are not available.

Today they are silently ignored and it could easily be missed that tests are not being picked up as expected.

[marcphilipp]

This applies to ClasspathRootSelector and ModuleSelector

[currenjin]

Hi, I’d like to work on this issue.

Plan:

• Validate search path roots provided to the Console Launcher and log any that are non-existent or unreadable.
• Based on @marcphilipp’s note, I’ll handle both ClasspathRootSelector and ModuleSelector.

Questions:

1. Preferred log level: INFO (visible by default) or DEBUG?
2. Should this logic live only in the console module, or also in the selector resolvers so other launchers can benefit?
3. Is it fine to include the problematic path verbatim in the log message?

Once I get confirmation on the above, I’ll open a PR with tests and an update to the User Guide.

[injae-kim]

Fix PR: #4823 👍