Repeating groups: Support for sorting by clicking column header

## Is your feature request related to a problem? Please describe
> A clear and concise description of what the problem is. Ex. I'm always frustrated when [...]

~~Listviwew~~ Repeating groups in apps does not support sorting by clicking the table column headers.

## Describe the solution you'd like
> A clear and concise description of what you want to happen.

* ~~Listview~~ repeating groups must support sorting by clicking on column headers. This is very similar to how Explorer in Windows works.
* Repeated clicks on the same column header should sort the list in ascending or descending order.
* There must be a visual clue that shows which column header has been clicked. This can be an icon above the column header that indicates whether the list is sorted in ascending or descending order.
* Sorting by clicking multiple column headers is not a requirement.

## Describe alternatives you've considered
> A clear and concise description of any alternative solutions or features you've considered.

## Additional context
> Add any other context or screenshots about the feature request here.

Start by locating the repeating-groups component and its column-header rendering in this TypeScript React frontend. Read the existing list and header interaction behavior, then verify ascending and descending toggling with a single active sort indicator; multiple-column sorting is not required.

Written by the indexing model from the issue text.