When var name is the same as var content, try to template it before reporting that var is not defined. (#13629)

* 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.

test/integration/roles/test_var_blending/tasks/main.yml

@@ -34,3 +34,15 @@
     that: 
         - 'diff_result.stdout == ""' 
 
+- name: check debug variable with same name as var content
+  debug: var=same_value_as_var_name_var
+  register: same_value_as_var_name
+
+- name: check debug variable output when variable is undefined
+  debug: var=undefined_variable
+  register: var_undefined
+
+- assert:
+    that:
+      - var_undefined.undefined_variable == 'VARIABLE IS NOT DEFINED!'
+      - same_value_as_var_name.same_value_as_var_name_var == 'same_value_as_var_name_var'

test/integration/roles/test_var_blending/vars/more_vars.yml

@@ -1 +1,3 @@
 badwolf: badwolf
+
+same_value_as_var_name_var: "same_value_as_var_name_var"