[ic-pagination-bar] - changing items per page causes immediate datatable change

[ad9242]

Summary of the bug

As mentioned under #3019, when changing the items per page on a pagination bar via keyboard navigation, the data-table updates immediately to the new length. It would be good if this could be changed only when enter is pressed

It should already be possible by setting the selectOnEnter prop to true

🪜 How to reproduce

Tell us the steps to reproduce the problem:

1. Go to page: data-table pagination storybook
2. Using keyboard tab to page length select control
3. Press the arrow down key
4. See the data-table length changes

🧐 Expected behaviour

To Be confirmed: the behaviour should either require pressing enter to select or be configurable

It needs to apply the the built in pagination bar or a custom slotted one