[Streaming API] Implement Authentication, Authorization, and Error Handling Across Streaming API

This issue impacts the following APIs:

1. Streaming API

• Acts as a wrapper around the Pipelines service.
• Must implement:
  • Authentication — Validate access tokens.
  • Authorization — Ensure users have the correct permissions for the requested operations.
• Must handle authentication and authorization errors properly, returning enough information for the Frontend to understand the issue (e.g., expired token, insufficient permissions, missing token).

You can find the guidelines for the Authorisation implementation in the Wiki FAQ: https://gitlab.eclipse.org/groups/eclipse-research-labs/datamite-project/-/wikis/home#access-control