Changes:
- Ensure proper shutdown in non-interactive mode
- Ensures the initial user prompt is logged in non-interactive mode
- Improve telemetry for streaming - handle chunks and input token count is now alongside other token counts in response
To test:
- Follow instructions in https://github.com/google-gemini/gemini-cli/blob/main/docs/core/telemetry.md#google-cloud
- Run CLI in non-interactive mode and observe logs/metrics in GCP Logs Explorer and Metrics Explorer
#750
