Sandbox message

[valoq]

When the landlock sandbox blocks file access, it previously triggered the same "Permission Denied" error message as DAC error (EACCES).
This patch does two things:

1. it checks the legitimate permission required by DAC before the sandbox is applied and reports any violation early (this should result in the same behavior from the user perspective when it comes to normal permission errors)
2. After the sandbox is activated, the EACCES error is treated as a landlock violation and reported differently with the following message:

Permission Denied! An Access Violation was prevented by the landlock sandbox.
This is most likely a bug in ouch, but could potentially indicate a prevented exploit attempt.
Please report the issue at https://github.com/ouch-org/ouch/issues and include the exact command used and if possible the archive file that triggered the issue. Do not submit sensitive data.

This should allow users to understand the correct nature of the error and provide a realistic feedback on how to treat this.

A regression in the error handling of rar was also fixed