feat(utils): add generic buildQueryString utility

- Add type-safe buildQueryString function to /utils
- Support primitives, arrays, and optional values
- Proper URL encoding for special characters
- Add comprehensive tests (25 test cases, all passing)
- Update Google Fonts API client to use shared utility
- Update Fontshare API client to use shared utility
- Export utility from /utils/index.ts

Benefits:
- DRY - Single source of truth for query string logic
- Type-safe - Proper TypeScript support with QueryParams type
- Tested - Comprehensive test coverage
- Maintainable - One place to fix bugs

src/entities/Font/model/stores/fontCollectionStore.ts

@@ -8,10 +8,7 @@
  */
 
 import type { UnifiedFont } from '$entities/Font/api/normalize';
-import {
-    type CollectionCacheManager,
-    createCollectionCache,
-} from '$shared/fetch/collectionCache';
+import { createCollectionCache } from '$shared/fetch/collectionCache';
 import type {
     Readable,
     Writable,