feat: implement pagination for PlayStore search

- Add `PlayStorePagingSource` and `PlayStorePagingRepository` to handle infinite scrolling for PlayStore apps

- Integrate Play Store paging flow into `SearchViewModelV2` and `SearchResultsContent`

- Create `PagingPlayStoreResultList` composable for displaying Play Store items

- Centralize icon URL generation in `Application` model and refactor adapters to use it

- Introduce `searchVersion` to properly reset scroll state on new search queries