feat: refactored the main validation logic

[srajasimman]

This pull request improves the robustness and flexibility of the commit message validation workflow and adds support for testing the codebase using Jest. The main changes include refactoring the commit message validation logic for better error handling and maintainability, enhancing the commit message pattern to support a wider range of valid scopes, and introducing Jest as a development dependency for testing.

Commit Message Validation Improvements:

• Refactored the main validation logic in commit-message-validator.js for better readability and maintainability, including extracting pattern construction to a separate function and improving error handling for invalid regex patterns.
• Enhanced the conventional commit message pattern to allow scopes with uppercase/lowercase letters, digits, underscores, slashes, and hyphens, making the validation more flexible.
• Improved error reporting by escaping backticks in invalid commit messages and providing more informative PR comments when validation fails.
• Added checks to skip validation for PRs with no commits or commits with empty messages, with appropriate log messages.

Testing Support:

• Added jest as a development dependency and configured it in package.json to enable testing with the Node environment and to match test files ending with .test.js.

[github-actions]

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❌ Commit 0ba724c has an invalid message format: "Add Jest as a dev dependency and configure test environment"

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