Clean up module documentation (#36909)

* Clean up module documentation

This PR includes:
- Removal of `default: None` (and variations)
- Removal of `required: false`
- Fixing booleans and `type: bool` where required

* Fix remaining (new) validation issues

lib/ansible/modules/cloud/cloudstack/cs_ip_address.py

@@ -55,8 +55,8 @@ options:
   poll_async:
     description:
       - Poll async jobs until job has finished.
-    default: yes
     type: bool
+    default: 'yes'
 extends_documentation_fragment: cloudstack
 '''