feat(artifact): updated proto and added client code (#185)

- **feat(artifact): updated proto and added client code**
- **fix(client): fixed client code**

Because

- lack of support for artifact backend

This commit

- added artifact client

happy path tested for the following functions

- [x] create_knowledge_base
- [x] upload_knowledge_base_file
- [x] list_knowledge_base_files
- [x] process_knowledge_base_files
- [x] list_knowledge_bases


![image](https://github.com/user-attachments/assets/df67c93a-272d-4eff-a4e9-30989907f2a9)