* When var name is the same as var content, try to template it before reporting that var is not defined.
Add asserts in test_var_blending to check this special corner case.
* Fix integration tests when using debug with list or dict.
now deprecation message appears with variable name in all spots where this occurs
debug's var= option is excluded as this is only place where bare variables shold actually
be accepted.
* 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
