(#20442)[PE-161] fix AIX extended attributes

Prior to this pull request, AIX extended attributes were completely broken, and had 0 tests.  This pulls makes these extended attributes such as those specified like
```puppet
user { "test1":
        ensure => present,
        uid => '123456',
        gid => 'system',
        shell => '/bin/ksh',
        home => '/home/test1',
        attributes => ["login=true", "rlogin=false"],
        managehome => true,
}

```
actually function properly.  

Additionally some tests were created; however, this provider is still **woefully** uncovered by tests.