Adjust test_prompt_generator and add test report generation

[younessZMZ]

Background

Add coverage report generation.
Adjust test_prompt_generator file.

Changes

• Remove unused imports.
• Add docstrings.
• Correct checking the presence of key-value pair of the command args dictionary in the generated prompt_string.
• Use setUpClass because we need one time execution of the setup function instead of setUp which is executed each time before each test function.
• Use covearge to load tests and adjust test location.
• Generate test report with missing tests to help in test integration.

Documentation

Test Plan

Tests impacted are passed before opening the PR.

PR Quality Checklist

• My pull request is atomic and focuses on a single change.
• I have thoroughly tested my changes with multiple different prompts.
• I have considered potential risks and mitigations for my changes.
• I have documented my changes clearly and comprehensively.
• I have not snuck in any "extra" small tweaks changes.