fix: fixed minor bug with utils/file exists() function

[ahmedosama94]

Description

While investigating an issue I had with the JSON loader, I found that the exists function does not work as intended. The node:fs/promises stat() function resolves with the stats data if the file exists, but the promise is rejected when the file does not exist, so the function never really returns false, swallowing the errors for getFiles in the parseTranslations() function as well as the new I18nError at the top of parseTranslations() after the exists() check.

I also came across this line

Using fs.stat() to check for the existence of a file before calling fs.open(), fs.readFile(), or fs.writeFile() is not recommended. Instead, user code should open/read/write the file directly and handle the error raised if the file is not available. To check if a file exists without manipulating it afterwards, fs.access() is recommended.
In the Node.JS docs here: https://nodejs.org/api/fs.html#fsstatpath-options-callback

So I also switched the implementation to use fs.access instead of fs.stat.

Linked Issues

Additional context

Quick view of the simple tests that I added:

and with the original implementation:

here are the test results:

and with the updated implementation:

here are the test results:

[coveralls]

coverage: 90.853% (+0.02%) from 90.829%
when pulling 7eb0864 on ahmedosama94:util-file-exists-fix
into 1efa63d on toonvanstrijp:main.