Implement content detectors on chat input

[evaline-ju]

Description

As a follow-up to the design in #167 , as an orchestrator developer I want to implement detections on chat completions input, with detectors that just work on content (like those that implement the /detection/content endpoint).

Discussion

Considerations will need to be made on "how much" of a particular chat history that detectors need to run on on each request, so this will be dependent on #193

Acceptance Criteria

• Unit tests cover new/changed code
• Examples build against new/changed code
• READMEs are updated
• Type of semantic version change is identified