feat: Add no-context option to server

[sachaarbonel]

feat: Add no-context option to server

This PR introduces a --no-context flag (and corresponding HTTP parameter no_context) to the server example. When set to true, the server will process audio requests without using the context from previous audio segments. This is useful for scenarios where each audio chunk should be treated independently.

Changes include:

• Added no_context boolean field to whisper_params.
• Updated command-line argument parsing and usage help text.
• Modified get_req_parameters to handle the no_context parameter from requests.
• Passed the no_context setting to whisper_full_params before processing.