Feature - Support GCP Secret Manager

[Benvii]

As we are already supporting AWS Secret Manager especially for Generative AI related secret management. At @theopenconversationkit/arkea we need support for GCP Secret Manager service.

This issue is main main issue for this introduction of this feature.

Related issues and PR :

• 📝 [Design] Introduce GCP Secrets for Gen AI services #1695 - [Design] Introduce GCP Secrets for Gen AI services  #1697
• No issue - 👨‍💻 [DERCBOT-1096] GCP Secret Manager Integration #1704

It will be followed by other issue if we decide to split the work of mainly implemented behind this issue. Technical design needs to be approved before starting any development work it will also serve as documentation for futur contributors.