Allow to sort search results

### Problem

No possibility to sort search results by latest release date.

### Proposal

Would be nice to sort search result by update date.
Probably some other sorting features might be useful like ratings.

### Prior Art (Optional)

_No response_

Start by locating the AppCenter search-results implementation and its existing result ordering. Determine whether the requested ordering is by latest release date or update date, define the behavior for that sort, and verify the result ordering with the relevant search tests; ratings are mentioned only as a possible future option.

Written by the indexing model from the issue text.