Implementing the ``chmod`` support

[webbunivAdmin]

Add chmod Support to Eio

This PR implements support for changing file permissions using the chmod operation in the Eio library. #764

Key Changes:

• Added chmod function that allows setting file permissions on a target resource:
  • Parameters:
    • ~follow: Determines whether to follow symlinks.
    • ~perm: Specifies the permission bits to set.
    • t: The target file or directory.
• Exception Handling:
  • Exceptions are handled to provide robust error reporting.
  • Context-aware re-raising of exceptions in case of failure for better debugging.
• Seamless Integration with Eio’s resource abstraction, supporting various permission modes.

Tests: