Include total amount of all existing entities in API response, when using search query params for paginated lists.

We have many lists in the new permissions management UI. When a list is empty we are showing the same message for:
- lists which are empty because no entities exist on the system
- lists which are empty because there is no search result for the provided search query params

It would be great to show a different message for each case. One solution could be, to return total amount of all entities, independently of the provided search. This way we could create a generic component which can be used for all paginated lists and which takes care of displaying the correct message for each scenario.