feat: add a reporter for Tavern testing framework

[gibiw]

This pull request introduces the integration of the qase-tavern package into the project, along with necessary configuration, documentation, and example tests. The most significant changes are the addition of the qase-tavern package, updates to the workflow configuration to include qase-tavern, and new example files demonstrating how to use qase-tavern for testing.

Integration of qase-tavern package:

• .github/workflows/pythonpackage.yml: Added qase-tavern to the list of projects in the matrix configuration for CI workflows. [1] [2]
• examples/tavern/requirements.txt: Added tavern and qase-tavern to the requirements file.

Documentation and configuration:

• examples/tavern/Readme.md: Added instructions on how to run the Tavern examples, including cloning the repository, installing dependencies, setting environment variables, and running the tests.
• examples/tavern/qase.config.json: Added a sample configuration file for qase-tavern with various settings for running tests and reporting results.
• qase-tavern/LICENSE.txt: Added the Apache License 2.0 for the qase-tavern package.
• qase-tavern/README.md: Added a README file for the qase-tavern package, including installation instructions, getting started guide, configuration options, and requirements.
• qase-tavern/changelog.md: Added a changelog file noting the first release of the qase-tavern package.

Example tests:

• examples/tavern/test_simple.tavern.yaml: Added simple test cases to demonstrate the use of qase-tavern for successful and failed tests.
• examples/tavern/test_with_id.tavern.yaml: Added test cases annotated with Qase IDs to demonstrate binding autotests to test cases in Qase.io.