[CLI] Remove session configs with write access

[patuwwy]

What?
Deleting only those configuration files to which we have write permission

If several users use si, configuration files may be created with different permissions (depending on the system settings - umask). If a user using si automatically creates a directory with the configuration for the current session, it may not be deleted by another user when the session ends.
I added a check to see if we have write access when filtering directories to delete

Review checks:

These aspects need to be checked by the reviewer:

• Verify and confirm operation (please post a screenshot)
• All STH tests pass
• All Scramjet Cloud Platform tests pass
• Documentation is updated or no changes

[alicja-gruzdz]

excellent, thanks, Patryk.
LInking issue #961