fix: fall back to default logs path in getPath('logs')

[codebytere]

Description of Change

Follow-up to #19545 (comment).

If users try to call app.getPath('logs') before they've called app.setAppLogsPath() then it would previously error. Apps that relied on getPath('log') to work would get an exception, which is not great API.

Now, calling app.getPath('logs') without having previously called app.setAppLogsPath() will result in a directory being created and set to /Library/Logs/YourAppName on macOS, and inside the userData directory on Linux and Windows.

This also adds a converter for base::Optional<T> such that we don't introduce the possibility for mate::Arguments* pollution a la https://xkcd.com/327.

cc @MarshallOfSound

Checklist

• PR description included and stakeholders cc'd
• npm test passes
• tests are changed or added
• relevant documentation is changed or added
• PR title follows semantic commit guidelines
• PR release notes describe the change in a way relevant to app developers, and are capitalized, punctuated, and past tense.

Release Notes

Notes: Fixed an issue where app.getPath('logs') would throw an error if the logs path was not previously set.

[ckerr]

The idea looks fine. A couple of nits in comments.

[MarshallOfSound]

Oh actually one final thing, can we put like a test for this somewhere 😆

[codebytere]

@MarshallOfSound should be all set now!

[release-clerk]

Release Notes Persisted

Fixed an issue where app.getPath('logs') would throw an error if the logs path was not previously set.

[trop]

I was unable to backport this PR to "6-0-x" cleanly;
you will need to perform this backport manually.

[trop]

I have automatically backported this PR to "7-0-x", please check out #19836

[trop]

A maintainer has manually backported this PR to "6-0-x", please check out #19955

[zcbenz]

@codebytere I just ran into this code when doing refactoring. I believe this should be if not otherwise the out would never be filled?