jsonify inventory (#32990)

* jsonify inventory
* smarter import, dont pass kwargs where not needed
* added datetime
* Eventual plan for json utilities to migrate to common/json_utils when we split
  basic.py no need to move jsonify to another file now as we'll do that later.
* json_dict_bytes_to_unicode and json_dict_unicode_to_bytes will also
  change names and move to common/text.py at that time (not to json).
  Their purpose is to recursively change the elements of a container
  (dict, list, set, tuple) into text or bytes, not to json encode or
  decode (they could be a generic precursor to that but are not limited
  to that.)
* Reimplement the private _SetEncoder which changes sets and datetimes
  into objects that are json serializable into a private function
  instead.  Functions are more flexible, less overhead, and simpler than
  an object.
* Remove code that handled simplejson-1.5.x and earlier.  Raise an error
  if that's the case instead.
  * We require python-2.6 or better which has the json module builtin to
    the stdlib.  So this is only an issue if the stdlib json has been
    overridden by a third party module and the simplejson on the system
    is 1.5.x or less.  (1.5 was released on 2007-01-18)

test/units/module_utils/test_basic.py

@@ -85,7 +85,9 @@ class TestModuleUtilsBasic(ModuleTestCase):
             if name == 'json':
                 raise ImportError
             elif name == 'simplejson':
-                return MagicMock()
+                sj = MagicMock()
+                sj.__version__ = '3.10.0'
+                return sj
             return realimport(name, *args, **kwargs)
 
         self.clear_modules(['json', 'ansible.module_utils.basic'])