[PR #6668/f3ecf4c7 backport][stable-7] ldap: Add client certificate support (#6696)

ldap: Add client certificate support (#6668)

* Set up secure ldap server

* ldap: Added client cert options

Shamelessly copied from https://github.com/andrewshulgin/ldap_search

* Added tests for ldap client authentication

* Add changelog fragment

* Make sure the openssl commands work on older versions of openssl

* Apply suggestions from code review

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

* Remove aliases for new arguments

* Add required_together to ldap module declerations

---------

Co-authored-by: Felix Fontein <felix@fontein.de>
(cherry picked from commit f3ecf4c7f8)

Co-authored-by: Gnonthgol <gnonthgol+github@gmail.com>

plugins/doc_fragments/ldap.py

@@ -29,6 +29,18 @@ options:
       - Set the path to PEM file with CA certs.
     type: path
     version_added: "6.5.0"
+  client_cert:
+    type: path
+    description:
+      - PEM formatted certificate chain file to be used for SSL client authentication.
+      - Required if O(client_key) is defined.
+    version_added: "7.1.0"
+  client_key:
+    type: path
+    description:
+      - PEM formatted file that contains your private key to be used for SSL client authentication.
+      - Required if O(client_cert) is defined.
+    version_added: "7.1.0"
   dn:
     required: true
     description: