[Harness] Fix/recall partial results

[jioffe502]

Description

This bulletproofs the harness in a way that still posts partial results even if the reranker or recall fails in some way. Also adds a fallback, if the reranker service is not started, to leverage the build endpoint if the api key is available

Checklist

• I am familiar with the Contributing Guidelines.
• New or existing tests cover these changes.
• The documentation is up to date with these changes.
• If adjusting docker-compose.yaml environment variables have you ensured those are mimicked in the Helm values.yaml file.