Add before payload to delete action in MongoDb connector

Hi,
For a need in our project, it will be usefull to have the payload of the deleted object in the move action of MongoDb.
The object contain references to do other action and the ID of the object is not enough.
I send the pull request to add a before payload when there is a remove action.
So for MongoDb connector we will have:
Create action -> after field with the content
Update action -> patch field with the content
Delete action -> before field with the action

Thanks