Fill up a upn_dns_info buffer and adds it to the pac.

Split ipadb_fill_info3 in 2 functions:
- one that retrieves basic account data and optionally fakes up some of
the data
- the other just fills info3 based on the input data as the name says

The StrEnum and Int tests are restructured to allow sharing the tests.
Individual *Enum tests are separated into methods.

Int already needed to take both int and long. This makes the functionality
available for all Param classes.

Options should be Param subclasses.

There is a special mode to set the ipaNTHash attribute if a RC4 Kerberos
key is available for the corresponding user. This is typically triggered
by samba via the ipa_sam passdb plugin. The principal used by samba to
connect to the IPA directory server has the right to modify ipaNTHash
but no other password attribute. This means that the current check on
the userPassword attribute is too strict for this case and leads to a
failure of the whole operation.

With this patch the access right on ipaNTHash are checked if no other
password operations are requested.