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/database/mysql/mysql_replication.py

@@ -29,7 +29,6 @@ options:
         description:
             - module operating mode. Could be getslave (SHOW SLAVE STATUS), getmaster (SHOW MASTER STATUS), changemaster (CHANGE MASTER TO), startslave
               (START SLAVE), stopslave (STOP SLAVE), resetslave (RESET SLAVE), resetslaveall (RESET SLAVE ALL)
-        required: False
         choices:
             - getslave
             - getmaster
@@ -88,8 +87,6 @@ options:
     master_auto_position:
         description:
             - does the host uses GTID based replication or not
-        required: false
-        default: null
         version_added: "2.0"
 
 extends_documentation_fragment: mysql