Cleanup handling of attributes in entity data tables.

## Description

Many pages implement the `EntityDataTable` component. Usually the related endpoint which fetches the entities (e.g. `/api/streams/paginated`) also returns the attributes which can be displayed as columns.

The idea behind this approach was that
- new attributes can be just defined in the backend, incl. the information if the attribute is sortable and filterable and the new columns are automatically available in the UI.
- we avoid displaying e.g. a sort icon in the UI while there is no related sort logic in the backend.

In the UI it is also possible to define aggregated columns, which do not exist as attributes in the related entity (e.g. throughput in streams overview).

Over the last years some columns have been defined in the UI, which actually are entity attributes and should be part of the backend response.

We need to have a look at every usage of the `PaginatedEntityDataTable` and check if attributes from the `tableLayout.additionalAttributes` prop can be moved into the `attributes` array in the backend response.

Example: `matched_at` in event definitions overview.