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/messaging/rabbitmq_parameter.py

@@ -26,32 +26,25 @@ options:
     description:
       - Name of the component of which the parameter is being set
     required: true
-    default: null
   name:
     description:
       - Name of the parameter being set
     required: true
-    default: null
   value:
     description:
       - Value of the parameter, as a JSON term
-    required: false
-    default: null
   vhost:
     description:
       - vhost to apply access privileges.
-    required: false
     default: /
   node:
     description:
       - erlang node name of the rabbit we wish to configure
-    required: false
     default: rabbit
     version_added: "1.2"
   state:
     description:
       - Specify if user is to be added or removed
-    required: false
     default: present
     choices: [ 'present', 'absent']
 '''