Adding Cancellation requests to websockets

[jay2jp]

WebSocket Cancellation Implementation

Added cancellation functionality to the WebSocket implementation, following the Cartesia API documentation.

Changes

1. Added new cancel method to _WebSocket class that implements the cancellation API described in: https://docs.cartesia.ai/api-reference/tts/working-with-web-sockets/contexts#cancelling-requests

2. Created separate request handling for cancellation to maintain API clarity:

   • Created new _construct_tts_request_cancel function to handle cancel requests
   • Kept cancellation separate from send method to preserve required parameters (model_id, transcript, output_format)
   • This aligns with the API's OR condition described in https://docs.cartesia.ai/api-reference/tts/tts#send

Implementation Notes

• Only implemented for _WebSocket class as it's our primary websocket implementation
• Did not implement for _TTSContext class due to limited experience with that component
• All changes have been tested in _WebSocket class and are working as expected

Documentation

i have added lines towards the end of the read me showing how this works