feat: add python diode otlp client support

[leoparente]

This pull request introduces support for a new client type, DiodeOTLPClient, across both the device discovery and worker components. The logic for client initialization now falls back to using DiodeOTLPClient when client credentials are not provided, improving flexibility for different deployment scenarios. Additionally, the main entry points for both components have been updated to reflect these changes, and unused credential checks have been removed.

Support for OTLP client initialization

• Added DiodeOTLPClient import and initialization logic in device_discovery/client.py and worker/policy/runner.py, enabling fallback to OTLP client when credentials are missing. [1] [2] [3] [4]

Updates to entry point scripts

• Removed mandatory checks for --diode-client-id and --diode-client-secret arguments in device_discovery/main.py and worker/main.py, allowing operation without these credentials. [1] [2]
• Updated client initialization logic in worker/main.py to ensure DiodeClient is only used when credentials are provided, otherwise falling back to OTLP client.