Update detector client for use of /api/v1/text/contents

[alanbraz]

Description

As a developer, I want to call any detector's API, so that I can use it correctly in my workflow.

Detector API is being revisited and we are adding more endpoints to nicely group together detectors in logical bins. This will result in changes in orchestrator.

Discussion

API updated and will need to refactor orchestrator code to accommodate them.

Acceptance Criteria

• update openapi spec for detectors: https://github.com/foundation-model-stack/fms-guardrails-orchestrator/blob/main/docs/api/openapi_detector_api.yaml
• update code to call detector that implements the new API

Note: this story only covers handing of classification type APIs. For other endpoints that we add to detector API, we will need to add respective APIs in orchestrator as well, which will be covered in different story.

[evaline-ju]

Removing blocked label - the switch to use /api/v1/text/contents instead of the current /api/v1/detector is unblocked for the existing orchestrator endpoints (classification / streaming-classification)