fix(config): Update clientlibs and renderClientLibs to read extraEntries correctly

[albertogarciaariza]

Description

This update ensures that the extraEntries are properly read and incorporated into the client library generation process.

Related Issue

Fixes #128

Types of changes

• [X] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• [X] My code follows the code style of this project.
• [X] I have read the CONTRIBUTING document.
• [X] All new and existing tests passed.

[Hugoer]

Hi team,

Thanks again for resolving the issue with the incorrect config path.

As a follow-up, there's now a real need to change the extraEntries field from an object to an array. This change is important to better support Webpack's advanced optimization configurations—particularly when generating separate files like runtime, chunks, and enabling treeshaking.

These setups can produce multiple output entries that need to be handled in a specific order or allow duplicate keys (e.g., for splitting or grouping), which a plain object structure can't support effectively. Using an array will provide the flexibility and control needed for these use cases.

Can you please update the structure and any related logic accordingly? 💜

Let me know if any clarification is needed!

Thanks!