[FEATURE] Support Speech OpenAI Audio API

[KaisNeffati]

This pull request introduces specific support for the speech synthesis feature of the OpenAI Audio API, directly addressing a part of the feature request #20, which was raised on March 12. These changes enable to leverage OpenAI's speech synthesis capabilities, expanding the suite of audio tools.

Key Features Introduced:

1. Speech API Integration: Created modules to handle requests to and from the OpenAI Audio API for generating speech. This integration includes handling constructing speech generation requests and processing responses with and without persistance.
2. Unit test: Include test for various use cases.
3. Examples and Documentation: Provided detailed examples showing how to utilize the speech synthesis API within our application. Updated the project documentation to include instructions on setting up and using the new speech features.
4. Error Handling: Implemented comprehensive error handling to address potential issues