Centering of components i repeating groups

### Description

Currently it is only possible to center text in columns of repeating groups. It would be nice to have the ability to center components (checkboxes, radiobuttons) as well.

### Additional Information

_No response_

Start by locating the repeating-group implementation and the code that centers text in its columns. Trace how checkbox and radio-button components are positioned there, then verify that both component types can be centered without changing other column alignment behavior.

Written by the indexing model from the issue text.