FastAPI Event Emitter and Coveralls.io Workflow

[mdapena]

Initial Checks

• The code compiles successfully without any errors or warnings.
• I have personally tested these changes on my local environment.
• I have ensured that relevant documentation has been added or updated.
• I adhere to the project structure and code standards defined in the documentation.
• My code follows the established coding style guidelines.
• I have added tests for the new code (if applicable).
• All existing tests have passed successfully.

Description

This pull request introduces new features such as the FastAPIEventEmitter and Coveralls.io workflow for coverage reports. It also includes fixes for minor errors in the Pyventus documentation.

• Added the FastAPIEventEmitter to enable smooth integration with the FastAPI framework and utilize its BackgroundTasks for event handling.
• Created comprehensive documentation for FastAPIEventEmitter, including tutorials and API references.
• Implemented a Coveralls.io workflow to generate a coverage badge and reports.
• Included permalinks for easy navigation within the documentation.
• Addressed minor errors in the Pyventus documentation.