New passkeyconfig management module

There is a new paskeyconfig management module placed in the plugins
folder:

    plugins/modules/ipapasskeyconfig.py

The paskeyconfig module allows to retrieve and modify global passkey
configuration attributes.

Here is the documentation of the module:

    README-passkeyconfig.md

New example playbooks have been added:

    playbooks/passkeyconfig/passkeyconfig-retrieve.yml
    playbooks/passkeyconfig/passkeyconfig-present.yml

New tests for the module can be found at:

    tests/passkeyconfig/test_passkeyconfig.yml
    tests/passkeyconfig/test_passkeyconfig_client_context.yml

Signed-off-by: Rafael Guterres Jeffman <rjeffman@redhat.com>

README-passkeyconfig.md

@@ -0,0 +1,88 @@
+Passkeyconfig module
+============
+
+Description
+-----------
+
+The passkeyconfig module allows to manage FreeIPA passkey configuration settings.
+
+Features
+--------
+
+* Passkeyconfig management
+
+
+Supported FreeIPA Versions
+--------------------------
+
+FreeIPA versions 4.4.0 and up are supported by the ipapasskeyconfig module.
+
+
+Requirements
+------------
+
+**Controller**
+* Ansible version: 2.15+
+
+**Node**
+* Supported FreeIPA version (see above)
+
+
+Usage
+=====
+
+Example inventory file
+
+```ini
+[ipaserver]
+ipaserver.test.local
+```
+
+
+By default, user verification for passkey authentication is turned on (`true`). Example playbook to ensure that the requirement for user verification for passkey authentication is turned off:
+
+```yaml
+---
+- name: Playbook to manage IPA passkeyconfig.
+  hosts: ipaserver
+  become: false
+
+  tasks:
+  - name: Ensure require_user_verification is false
+    ipapasskeyconfig:
+      ipaadmin_password: SomeADMINpassword
+      require_user_verification: false
+```
+
+
+Example playbook to get current passkeyconfig:
+
+```yaml
+---
+- name: Playbook to get IPA passkeyconfig.
+  hosts: ipaserver
+  become: false
+
+  tasks:
+  - name: Retrieve current passkey configuration
+    ipapasskeyconfig:
+      ipaadmin_password: SomeADMINpassword
+```
+
+
+Variables
+---------
+
+Variable | Description | Required
+-------- | ----------- | --------
+`ipaadmin_principal` | The admin principal is a string and defaults to `admin` | no
+`ipaadmin_password` | The admin password is a string and is required if there is no admin ticket available on the node | no
+`ipaapi_context` | The context in which the module will execute. Executing in a server context is preferred. If not provided context will be determined by the execution environment. Valid values are `server` and `client`. | no
+`ipaapi_ldap_cache` | Use LDAP cache for IPA connection. The bool setting defaults to true. (bool) | no
+`require_user_verification` \| `iparequireuserverification` | Require user verification for passkey authentication. (bool) | no
+
+
+Authors
+=======
+
+Rafael Guterres Jeffman