ansible_freeipa_module_utils: Add EntryFactory class

This patch adds the class EntryFactory to the ansible-freeipa module
utils. This class allows the handling of modules with multiple object
entries as list of objects. When the multi-object parameter is not used,
it creates a list of a single object, allowing for the same code idiom
to be used.

The entries created can be used both as objects, by acessing the values
as properties, or as dictionaires, by accessing the elements as
key-value pairs.