[EuiDataGrid] Make `EuiDataGridCellActions` reusable outside `EuiDataGrid`

**Is your feature request related to a problem? Please describe.**
`EuiDataGridCellActions` are only available as part of `EuiDataGrid`. It would be useful to use this for other use cases, specifically integrating it in `EuiTable` like in this design:

**Describe the solution you'd like**
Split `EuiDataGridCellActions` out of EuiDataGrid.

**Describe alternatives you've considered**
I should be possible to use it that way outside `EuiDataGrid`. It's not exported, though, and by that it's not part of the supported EUI API.

It would also only be the cell actions bar, not the whole cell wrapper and selection thing, so there would be plenty to handle on your end in terms of accessibility

**Desired timeline**
I believe that @patpscal and team will go with another solution for now, so we can consider this was low priority at the moment.

**Additional context**
This would be a great opportunity to explore splitting up the `EuiDataGrid` logic from the UI elements. Consider this issue an experimentation ground. The exported component should be marked as experimental.