Render unit test suite results in Livebook notes

[Kavignon]

Ensure that when a module with attached unit tests is evaluated in the Livebook, the test results are displayed directly in the notebook, with visual indicators for pass/fail status.

Tasks

• Set up a function in Livebook to load and run the unit tests attached to the evaluated module.
• Capture the test results, displaying ✅ for passed tests and ❌ for failed ones.
• Structure the output to include test names and results for easy interpretation in the notebook.
• Ensure this mechanism doesn’t interfere with other parts of the notebook or Livebook’s interactive elements.