Refactor: simplify search logic

This commit refactors the search functionality by:
- Consolidating `getCleanApkSearchResults` and `getGplaySearchResult` into a single `search` method in `SearchApi` and `SearchApiImpl`.
- Moving the search logic from `SearchViewModel` to `SearchApiImpl`.
- `SearchApiImpl` now directly calls `SearchProvider` methods for searching by package name and keyword.
- Package name searches are now performed only if the query matches a package name pattern.
- Search result fetching in `SearchViewModel` is simplified to a single call to `searchApi.search(query)`.
- Constants for app types (`APP_TYPE_ANY`, `APP_TYPE_OPEN`, `APP_TYPE_PWA`) are moved from `SearchApi` to `ApplicationRepository`.
- Removed unused `coroutineScope` and `async` calls in `SearchApiImpl`.