When comparing a module argument set against an IPA argument set, for
each attribute, if it is a list or tuple, a set is created and the sets
are compared, this is more efficient than comparing the objects
individually, as the list order may be different, and using a set,
ordering is ignored. If the parameter value is a scalar, they are
directly compared.

Although efficient, this method causes idempotence issues with some data
types, for example, when the comparison of two strings must be case
insensitive.

The solution proposed here is to avoid direct value comparison by always
using the set comparison method, and that the data type of the values
stored in the sets can perform the proper comparison for the specific
data type.

To ensure the comparison is done only with sets, scalar values are
"wrapped" in a list, and the list is later converted to a set.

To cope with specific data type comparison (for example: hostnames,
services, or case insensitive strings) a new parameter was added, so a
dictionaire mapping an argument to a conversion function can be passed,
and the set of values is created by applying the conversion function to
the IPA and the argument values.

The complexity order of the comparison algorithm is not changed, but
data conversion, and possibly a customized comparison, are new
operations performed, which may have some impact on the execution time.

One of the issues on ensuring idempotence behavior is that FreeIPA does
not expose datatypes along with the values stored in objects.

By treating data returned from FreeIPA API with the proper datatype, it
is easier to ensure that comparisons that will trigger changes (or not)
are properly executed, despite of the stored value or the provided
parameter data.

This patch provides an initial implementation of the datatypes used by
ansible-freeipa modules. An implementation for 'hostname' which ensures
data provided for hostnames contain a fully qualified hostname, always
in lower case, and an implementation of a 'list_of' to allow for
parameters which are lists of objects of a specific datatype.

Adapt plugin to use the 'hostname' datatype, instead of reimplementing
the required operations.

Adapt plugin to use the 'hostname' datatype, instead of reimplementing
the required operations.

Adapt plugin to use the 'hostname' datatype, instead of reimplementing
the required operations.

Adapt plugin to use the 'hostname' datatype, instead of reimplementing
the required operations.

Adapt plugin to use the 'hostname' datatype, instead of reimplementing
the required operations.

Add a service cast function that expose an object that allows services
to be compared in a case-insensitive manner, but preserve case of the
original data.

Adapt plugin to use the 'service' datatype, instead of reimplementing
the required operations.

Adapt plugin to use the 'service' datatype, instead of reimplementing
the required operations.

Add a cast function to create a string that can be compared in a case
insensitive manner. It also allows the use of the objects in sets and
dictionaries, making the key case insensitive.

Several parameters for ipadelegation need to be compared in a case
insensitive manner. Most should be stored in lowercase, but 'memberof'
should preserve case to maintain the same behavior as IPA CLI commands.

The list generation functions for adding and deleting members from IPA
objects create sets but are not aware of the underlying attribute data
type. Some data types need to perform special comparison, like case
insensitive string comparison, or ensure the existence of a FQDN.

This patch adds a new optional attribute to the list generation
functions, 'attr_datatype', that takes a function able to convert the
expected data (usually a string) to an object that will correctly handle
hashing and data comparison.

The functions were also modified to perform the list generation, but
still return the same data provided to the caller, withot conversion,
minimizing the required amount of code changes.

FreeIPA provides a default hbacsvcgroup named "Sudo", with capital S,
that is different from every other hbacsvcgroup, which are all
represented by lower case letters.

As data from IPA API was not modified, this causes an idempotence error
when using different capitalization with the 'hbacsvcgroup' parameter.

This patch fixes the issue by using the CaseInsensitive comparator to
create the hbacsvcgroup list.

Tests were update to make sure a regression is not included in the
future.

ipahostgroup parameters 'host', 'hostgroup', 'membermanager_user' and
'membermanager_group' must be compared in a case insensitive manner
and stored as lower case strings.

This patch fixes the comparison and storage of this parameters, and
change the handling of members to use the same structure as in newer
modules.

Two new tests files were added:

    tests/hostgroup/test_hostgroup_case_insensitive.yml
    tests/hostgroup/test_hostgroup_membermanager_case_insensitive.yml

Some attributes for ipagroup objects are stored using lower case letters
and should be converted upon retrieving parameter data.

This patch adds the missing conversion and provides a new test playbook:

    tests/group/test_group_case_insensitive.yml