This feature is already here - if you want users to be able to delete messages, as an owner simply go to the three dots (...) next to the Team > Manage Team > Settings. You have the options for whether users can delete messages.
If you want owners to be able to delete messages of user then you will need to check to make sure that the option is set to on in the messaging policy in the Teams Admin Centre.
Hope that answers your question!
Best, Chris