Before this commit, it was not possible to show a message using a client
action. (e.g. show a success message only with core in Python)
Now, it's possible using a client action. This client action call
displayNotification and so we can use the same options also.
A test is added to be sure that this action do not change the current action
Note: in the future a custom registry may be created in a refactoring
to specific function action registry.
X-original-commit: 8775fd670b6b3ec19a77fc0eab72d2223baa36c8
Romeo Fragomeli
547d2d87fc