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/utils/module_docs_fragments/junos.py

@@ -29,7 +29,6 @@ options:
       - For more information please see the L(Junos OS Platform Options guide, ../network/user_guide/platform_junos.html).
       - HORIZONTALLINE
       - A dict object containing connection details.
-    default: null
     suboptions:
       host:
         description:
@@ -56,7 +55,6 @@ options:
             the remote device.   This value is used to authenticate
             the SSH session. If the value is not specified in the task, the
             value of environment variable C(ANSIBLE_NET_PASSWORD) will be used instead.
-        default: null
       timeout:
         description:
           - Specifies the timeout in seconds for communicating with the network device