Two fixes to action plugins

* Fix the task_vars parameter to not default to a mutable type (dict)
* Implement invocation in the base class's run() method have each action
  module call the run() method's implemention in the base class.
* Return values from the action plugins' run() method takes the return
  value from the base class run() method into account so that invocation
  makes its way to the output.

Fixes #12869

lib/ansible/plugins/action/win_template.py

@@ -22,6 +22,7 @@ __metaclass__ = type
 from ansible.plugins.action import ActionBase
 from ansible.plugins.action.template import ActionModule as TemplateActionModule
 
+
 # Even though TemplateActionModule inherits from ActionBase, we still need to
 # directly inherit from ActionBase to appease the plugin loader.
 class ActionModule(TemplateActionModule, ActionBase):