test: add unit tests for poultry repository and searchable dropdown functionalities

- Introduced tests for `PoultryScienceRepositoryImp` to validate delegated remote calls.
- Added comprehensive tests for `SearchableDropdownLogic` covering selection, overlay, and search logic.
- Enhanced `SearchableDropdown` widget tests for multi-select, label building, and overlay management.

packages/chicken/test/data/data_source/remote/auth/auth_remote_imp_test.dart

@@ -323,7 +323,7 @@ void main() {
           ).thenAnswer((_) async => mockResponse);
 
           // Act
-          await authRemoteDataSource.submitUserInfo(userInfo);
+          await authRemoteDataSource.stewardAppLogin(token: 'test-token', queryParameters: userInfo);
 
           // Assert
           verify(