ipauser: Use PARAM_MAPPING and query state support

The ipauser module has been reworked to use the new PARAM_MAPPING added
to ansible_freeipa_module.

The member handling for manager, principal, certificate and certmapdata
has been simplified by using gen_member_add_del_lists. The member
entries in PARAM_MAPPING are now marked with "member": True. This
replaces the manual calls to gen_add_del_lists, gen_add_list and
gen_intersection_list across three separate action/state branches with
a single unified call.

The new query state allows to retrieve user information from IPA.
The query_param option controls which fields are returned: BASE for
essential fields, ALL for all fields, PKEY_ONLY for user names only,
or a list of specific field names.

Here is the updated documentation of the module:

    README-user.md

New tests for the query state can be found at:

    tests/user/test_user_query.yml

tests/user/test_user.yml

@@ -128,6 +128,22 @@
     register: result
     failed_when: result.changed or result.failed
 
+  - name: User pinky with email "pinky"
+    ipauser:
+      ipaadmin_password: SomeADMINpassword
+      name: pinky
+      email: pinky
+    register: result
+    failed_when: not result.changed or result.failed
+
+  - name: User pinky with email "pinky", again
+    ipauser:
+      ipaadmin_password: SomeADMINpassword
+      name: pinky
+      email: pinky
+    register: result
+    failed_when: result.changed or result.failed
+
   - name: User pinky present with changed settings
     ipauser:
       ipaadmin_password: SomeADMINpassword