keycloak: add support for client_credentials authentication (#10231)

* add client_credentials authentication for keycloak tasks incl. test case

* support client credentials in all keycloak modules

* Add changelog fragment

* fix typos in required list

* Update changelogs/fragments/10231-keycloak-add-client-credentials-authentication.yml

Co-authored-by: Felix Fontein <felix@fontein.de>

* revert keycloak url in test environment

---------

Co-authored-by: Felix Fontein <felix@fontein.de>

plugins/modules/keycloak_user_rolemapping.py

@@ -242,9 +242,9 @@ def main():
 
     module = AnsibleModule(argument_spec=argument_spec,
                            supports_check_mode=True,
-                           required_one_of=([['token', 'auth_realm', 'auth_username', 'auth_password'],
+                           required_one_of=([['token', 'auth_realm', 'auth_username', 'auth_password', 'auth_client_id', 'auth_client_secret'],
                                              ['uid', 'target_username', 'service_account_user_client_id']]),
-                           required_together=([['auth_realm', 'auth_username', 'auth_password']]),
+                           required_together=([['auth_username', 'auth_password']]),
                            required_by={'refresh_token': 'auth_realm'},
                            )